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Sample records for relative permeability functions

  1. Experimental Measurement of Relative Permeability Functions for Fuel Cell GDL Materials

    KAUST Repository

    Hussaini, Irfan; Wang, Chao-Yang

    2009-01-01

    Gas diffusion layer in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions. In the present work, air and water relative permeabilities are experimentally determined as functions of saturation for typical GDL materials such as Toray-060, -090, -120 carbon paper and E-Tek carbon cloth materials in their plain, untreated forms. Saturation is measured using an ex-situ gravimetric method. Absolute and relative permeability functions in the two directions of interest are presented. Significant departure from the generally assumed cubic function of saturation is observed. ©The Electrochemical Society.

  2. Verification of capillary pressure functions and relative permeability equations for gas production

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jaewon [Arizona State Univ., Tempe, AZ (United States)

    2016-10-25

    The understanding of multiphase fluid flow in porous media is of great importance in many fields such as enhanced oil recovery, hydrology, CO2 sequestration, contaminants cleanup and natural gas production from hydrate bearing sediments. However, there are many unanswered questions about the key parameters that characterize gas and water flows in porous media. The characteristics of multiphase fluid flow in porous media such as water retention curve, relative permeability, preferential fluid flow patterns and fluid-particle interaction should be taken into consideration for a fundamental understanding of the behavior of pore scale systems.

  3. Relative Permeability of Fractured Rock

    Energy Technology Data Exchange (ETDEWEB)

    Mark D. Habana

    2002-06-30

    Contemporary understanding of multiphase flow through fractures is limited. Different studies using synthetic fractures and various fluids have yielded different relative permeability-saturation relations. This study aimed to extend the understanding of multiphase flow by conducting nitrogen-water relative permeability experiments on a naturally-fractured rock from The Geysers geothermal field. The steady-state approach was used. However, steady state was achieved only at the endpoint saturations. Several difficulties were encountered that are attributed to phase interference and changes in fracture aperture and surface roughness, along with fracture propagation/initiation. Absolute permeabilities were determined using nitrogen and water. The permeability values obtained change with the number of load cycles. Determining the absolute permeability of a core is especially important in a fractured rock. The rock may change as asperities are destroyed and fractures propagate or st rain harden as the net stresses vary. Pressure spikes occurred in water a solute permeability experiments. Conceptual models of an elastic fracture network can explain the pressure spike behavior. At the endpoint saturations the water relative permeabilities obtained are much less than the nitrogen gas relative permeabilities. Saturations were determined by weighing and by resistivity calculations. The resistivity-saturation relationship developed for the core gave saturation values that differ by 5% from the value determined by weighing. Further work is required to complete the relative permeability curve. The steady-state experimental approach encountered difficulties due to phase interference and fracture change. Steady state may not be reached until an impractical length of time. Thus, unsteady-state methods should be pursued. In unsteady-state experiments the challenge will be in quantifying rock fracture change in addition to fluid flow changes.

  4. Steam-water relative permeability

    Energy Technology Data Exchange (ETDEWEB)

    Ambusso, W.; Satik, C.; Home, R.N. [Stanford Univ., CA (United States)

    1997-12-31

    A set of relative permeability relations for simultaneous flow of steam and water in porous media have been measured in steady state experiments conducted under the conditions that eliminate most errors associated with saturation and pressure measurements. These relations show that the relative permeabilities for steam-water flow in porous media vary approximately linearly with saturation. This departure from the nitrogen/water behavior indicates that there are fundamental differences between steam/water and nitrogen/water flows. The saturations in these experiments were measured by using a high resolution X-ray computer tomography (CT) scanner. In addition the pressure gradients were obtained from the measurements of liquid phase pressure over the portions with flat saturation profiles. These two aspects constitute a major improvement in the experimental method compared to those used in the past. Comparison of the saturation profiles measured by the X-ray CT scanner during the experiments shows a good agreement with those predicted by numerical simulations. To obtain results that are applicable to general flow of steam and water in porous media similar experiments will be conducted at higher temperature and with porous rocks of different wetting characteristics and porosity distribution.

  5. A relative permeability model to derive fractional-flow functions of water-alternating-gas and surfactant-alternating-gas foam core-floods

    International Nuclear Information System (INIS)

    Al-Mossawy, Mohammed Idrees; Demiral, Birol; Raja, D M Anwar

    2013-01-01

    Foam is used in enhanced oil recovery to improve the sweep efficiency by controlling the gas mobility. The surfactant-alternating-gas (SAG) foam process is used as an alternative to the water-alternating-gas (WAG) injection. In the WAG technique, the high mobility and the low density of the gas lead the gas to flow in channels through the high permeability zones of the reservoir and to rise to the top of the reservoir by gravity segregation. As a result, the sweep efficiency decreases and there will be more residual oil in the reservoir. The foam can trap the gas in liquid films and reduces the gas mobility. The fractional-flow method describes the physics of immiscible displacements in porous media. Finding the water fractional flow theoretically or experimentally as a function of the water saturation represents the heart of this method. The relative permeability function is the conventional way to derive the fractional-flow function. This study presents an improved relative permeability model to derive the fractional-flow functions for WAG and SAG foam core-floods. The SAG flow regimes are characterized into weak foam, strong foam without a shock front and strong foam with a shock front. (paper)

  6. Measurement of relative permeability of fuel cell diffusion media

    KAUST Repository

    Hussaini, I.S.; Wang, C.Y.

    2010-01-01

    Gas diffusion layer (GDL) in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions

  7. Measurement of relative permeability of fuel cell diffusion media

    KAUST Repository

    Hussaini, I.S.

    2010-06-01

    Gas diffusion layer (GDL) in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions. In the present work, air and water relative permeabilities are experimentally determined as functions of saturation for typical GDL materials such as Toray-060, -090, -120 carbon paper and E-Tek carbon cloth materials in their plain, untreated forms. Saturation is measured using an ex situ gravimetric method. Absolute and relative permeability functions in the two directions of interest are presented and new correlations for in-plane relative permeability of water and air are established. © 2010 Elsevier B.V. All rights reserved.

  8. A Reconciliation of Packed Column Permeability Data: Column Permeability as a Function of Particle Porosity

    Directory of Open Access Journals (Sweden)

    Hubert M. Quinn

    2014-01-01

    Full Text Available In his textbook teaching of packed bed permeability, Georges Guiochon uses mobile phase velocity as the fluid velocity term in his elaboration of the Darcy permeability equation. Although this velocity frame makes a lot of sense from a thermodynamic point of view, it is valid only with respect to permeability at a single theoretical boundary condition. In his more recent writings, however, Guiochon has departed from his long-standing mode of discussing permeability in terms of the Darcy equation and has embraced the well-known Kozeny-Blake equation. In this paper, his teaching pertaining to the constant in the Kozeny-Blake equation is examined and, as a result, a new correlation coefficient is identified and defined herein based on the velocity frame used in his teaching. This coefficient correlates pressure drop and fluid velocity as a function of particle porosity. We show that in their experimental protocols, Guiochon et al. have not adhered to a strict material balance of permeability which creates a mismatch of particle porosity and leads to erroneous conclusions regarding the value of the permeability coefficient in the Kozeny-Blake equation. By correcting the experimental data to properly reflect particle porosity we reconcile the experimental results of Guiochon and Giddings, resulting in a permeability reference chart which is presented here for the first time. This reference chart demonstrates that Guiochon’s experimental data, when properly normalized for particle porosity and other related discrepancies, corroborates the value of 267 for the constant in the Kozeny-Blake equation which was derived by Giddings in 1965.

  9. Analytical Estimation of Water-Oil Relative Permeabilities through Fractures

    Directory of Open Access Journals (Sweden)

    Saboorian-Jooybari Hadi

    2016-05-01

    Full Text Available Modeling multiphase flow through fractures is a key issue for understanding flow mechanism and performance prediction of fractured petroleum reservoirs, geothermal reservoirs, underground aquifers and carbon-dioxide sequestration. One of the most challenging subjects in modeling of fractured petroleum reservoirs is quantifying fluids competition for flow in fracture network (relative permeability curves. Unfortunately, there is no standard technique for experimental measurement of relative permeabilities through fractures and the existing methods are very expensive, time consuming and erroneous. Although, several formulations were presented to calculate fracture relative permeability curves in the form of linear and power functions of flowing fluids saturation, it is still unclear what form of relative permeability curves must be used for proper modeling of flow through fractures and consequently accurate reservoir simulation. Basically, the classic linear relative permeability (X-type curves are used in almost all of reservoir simulators. In this work, basic fluid flow equations are combined to develop a new simple analytical model for water-oil two phase flow in a single fracture. The model gives rise to simple analytic formulations for fracture relative permeabilities. The model explicitly proves that water-oil relative permeabilities in fracture network are functions of fluids saturation, viscosity ratio, fluids density, inclination of fracture plane from horizon, pressure gradient along fracture and rock matrix wettability, however they were considered to be only functions of saturations in the classic X-type and power (Corey [35] and Honarpour et al. [28, 29] models. Eventually, validity of the proposed formulations is checked against literature experimental data. The proposed fracture relative permeability functions have several advantages over the existing ones. Firstly, they are explicit functions of the parameters which are known for

  10. Calculation of large scale relative permeabilities from stochastic properties of the permeability field and fluid properties

    Energy Technology Data Exchange (ETDEWEB)

    Lenormand, R.; Thiele, M.R. [Institut Francais du Petrole, Rueil Malmaison (France)

    1997-08-01

    The paper describes the method and presents preliminary results for the calculation of homogenized relative permeabilities using stochastic properties of the permeability field. In heterogeneous media, the spreading of an injected fluid is mainly sue to the permeability heterogeneity and viscosity fingering. At large scale, when the heterogeneous medium is replaced by a homogeneous one, we need to introduce a homogenized (or pseudo) relative permeability to obtain the same spreading. Generally, is derived by using fine-grid numerical simulations (Kyte and Berry). However, this operation is time consuming and cannot be performed for all the meshes of the reservoir. We propose an alternate method which uses the information given by the stochastic properties of the field without any numerical simulation. The method is based on recent developments on homogenized transport equations (the {open_quotes}MHD{close_quotes} equation, Lenormand SPE 30797). The MHD equation accounts for the three basic mechanisms of spreading of the injected fluid: (1) Dispersive spreading due to small scale randomness, characterized by a macrodispersion coefficient D. (2) Convective spreading due to large scale heterogeneities (layers) characterized by a heterogeneity factor H. (3) Viscous fingering characterized by an apparent viscosity ration M. In the paper, we first derive the parameters D and H as functions of variance and correlation length of the permeability field. The results are shown to be in good agreement with fine-grid simulations. The are then derived a function of D, H and M. The main result is that this approach lead to a time dependent . Finally, the calculated are compared to the values derived by history matching using fine-grid numerical simulations.

  11. Herbal medicines that benefit epidermal permeability barrier function

    Directory of Open Access Journals (Sweden)

    Lizhi Hu

    2015-06-01

    Full Text Available Epidermal permeability barrier function plays a critical role in regulating cutaneous functions. Hence, researchers have been searching for effective and affordable regimens to enhance epidermal permeability barrier function. In addition to topical stratum corneum lipids, peroxisome proliferator-activated receptor, and liver X receptor ligands, herbal medicines have been proven to benefit epidermal permeability barrier function in both normal and diseased skin, including atopic dermatitis, glucocorticoid-induced skin damage, and UVB-damaged skin. The potential mechanisms by which herbal medicines improve the permeability barrier include stimulation of epidermal differentiation, lipid production, antimicrobial peptide expression, and antioxidation. Therefore, utilization of herbal medicines could be a valuable alternative approach to enhance epidermal permeability barrier function in order to prevent and/or treat skin disorders associated with permeability barrier abnormalities.

  12. microRNA-4516 Contributes to Different Functions of Epithelial Permeability Barrier by Targeting Poliovirus Receptor Related Protein 1 in Enterovirus 71 and Coxsackievirus A16 Infections

    Directory of Open Access Journals (Sweden)

    Yajie Hu

    2018-04-01

    Full Text Available Enterovirus 71 (EV-A71 and coxsackievirus A16 (CV-A16 remain the predominant etiological agents of hand, foot, and mouth disease (HFMD. The clinical manifestations caused by the two viruses are obviously different. CV-A16 usually triggers a repeated infection, and airway epithelial integrity is often the potential causative factor of respiratory repeated infections. Our previous studies have demonstrated that there were some differentially expressed miRNAs involved in the regulation of adhesion function of epithelial barrier in EV-A71 and CV-A16 infections. In this study, we compared the differences between EV-A71 and CV-A16 infections on the airway epithelial barrier function in human bronchial epithelial (16HBE cells and further screened the key miRNA which leaded to the formation of these differences. Our results showed that more rapid proliferation, more serious destruction of 16HBE cells permeability, more apoptosis and disruption of intercellular adhesion-associated molecules were found in CV-A16 infection as compared to EV-A71 infection. Furthermore, we also identified that microRNA-4516 (miR-4516, which presented down-regulation in EV-A71 infection and up-regulation in CV-A16 infection was an important regulator of intercellular junctions by targeting Poliovirus receptor related protein 1(PVRL1. The expressions of PVRL1, claudin4, ZO-1 and E-cadherin in CV-A16-infected cells were significantly less than those in EV-A71-infected cells, while the expressions of these proteins were subverted when pre-treated with miR-4516-overexpression plasmid in EV-A71 infected and miR-4516-knockdown plasmid in CV-A16 infected 16HBE cells. Thus, these data suggested that the opposite expression of miR-4516 in EV-A71 and CV-A16 infections might be the initial steps leading to different epithelial impairments of 16HBE cells by destroying intercellular adhesion, which finally resulted in different outcomes of EV-A71 and CV-A16 infections.

  13. Sub-core permeability and relative permeability characterization with Positron Emission Tomography

    Science.gov (United States)

    Zahasky, C.; Benson, S. M.

    2017-12-01

    This study utilizes preclinical micro-Positron Emission Tomography (PET) to image and quantify the transport behavior of pulses of a conservative aqueous radiotracer injected during single and multiphase flow experiments in a Berea sandstone core with axial parallel bedding heterogeneity. The core is discretized into streamtubes, and using the micro-PET data, expressions are derived from spatial moment analysis for calculating sub-core scale tracer flux and pore water velocity. Using the flux and velocity data, it is then possible to calculate porosity and saturation from volumetric flux balance, and calculate permeability and water relative permeability from Darcy's law. Full 3D simulations are then constructed based on this core characterization. Simulation results are compared with experimental results in order to test the assumptions of the simple streamtube model. Errors and limitations of this analysis will be discussed. These new methods of imaging and sub-core permeability and relative permeability measurements enable experimental quantification of transport behavior across scales.

  14. Permeability criteria for effective function of passive countercurrent multiplier.

    Science.gov (United States)

    Layton, H E; Knepper, M A; Chou, C L

    1996-01-01

    The urine concentrating effect of the mammalian renal inner medulla has been attributed to countercurrent multiplication of a transepithelial osmotic difference arising from passive absorption of NaCl from thin ascending limbs of long loops of Henle. This study assesses, both mathematically and experimentally, whether the permeability criteria for effective function of this passive hypothesis are consistent with transport properties measured in long loops of Henle of chinchilla. Mathematical simulations incorporating loop of Henle transepithelial permeabilities idealized for the passive hypothesis generated a steep inner medullary osmotic gradient, confirming the fundamental feasibility of the passive hypothesis. However, when permeabilities measured in chinchilla were used, no inner medullary gradient was generated. A key parameter in the apparent failure of the passive hypothesis is the long-loop descending limb (LDL) urea permeability, which must be small to prevent significant transepithelial urea flux into inner medullary LDL. Consequently, experiments in isolated perfused thin LDL were conducted to determine whether the urea permeability may be lower under conditions more nearly resembling those in the inner medulla. LDL segments were dissected from 30-70% of the distance along the inner medullary axis of the chinchilla kidney. The factors tested were NaCl concentration (125-400 mM in perfusate and bath), urea concentration (5-500 mM in perfusate and bath), calcium concentration (2-8 mM in perfusate and bath), and protamine concentration (300 micrograms/ml in perfusate). None of these factors significantly altered the measured urea permeability, which exceeded 20 x 10(-5) cm/s for all conditions. Simulation results show that this moderately high urea permeability in LDL is an order of magnitude too high for effective operation of the passive countercurrent multiplier.

  15. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of a health claim related to flaxseed oil and vitamin E and maintenance of the skin permeability barrier function pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    related to a combination of flaxseed oil and vitamin E and maintenance of the skin permeability barrier function. The food constituent that is the subject of the health claim is a combination of flaxseed oil and vitamin E. The Panel considers that the combination of flaxseed oil and vitamin E...... be drawn from these studies for the scientific substantiation of the claim. The Panel concludes that a cause and effect relationship has not been established between the consumption of a combination of flaxseed oil and vitamin E and maintenance of the skin permeability barrier function...... is sufficiently characterised. The claimed effect is “contributes to maintain skin permeability barrier function”. The target population proposed by the applicant is healthy adults with dry and sensitive skin. Maintenance of the permeability barrier function of the skin is a beneficial physiological effect...

  16. Relative permeability of the endothelium and epithelium of rabbit lungs

    International Nuclear Information System (INIS)

    Effros, R.M.; Mason, G.R.; Silverman, P.; Hukkanen, J.

    1986-01-01

    Electron micrographic studies of lungs suggest that the epithelial cells are more tightly joined than the underlying endothelium, and macromolecules penetrate the endothelium more readily than the epithelium. Comparisons of epithelial and endothelial permeability to small molecules have been based upon the relative rates at which solutes traverse the alveolar-capillary barrier in fluid filled lungs and those at which they equilibrate across the capillaries in air-filled lungs. Because the former process is much slower than the latter, it has been concluded that the epithelium is less permeable to small solutes than the endothelium. However this difference may be related to inadequate access of solutes to airway surfaces. In this study, solute losses from the vascular space were compared to those from the airspace in perfused, fluid-filled rabbit lungs. 36 Cl - and 125 I - were lost from air-spaces almost twice as rapidly as 22 Na + . In contrast, the endothelium is equally permeable to 22 Na + and these anions. Loss of 3 H-mannitol from the perfusate resembled that of 22 Na + for about 30 minutes, after which diffusion of 3 H-mannitol into the tissue nearly ceased. These observations suggest that the epithelium is more permselective than the endothelium. By resisting solute and water transport, the epithelium tends to prevent alveolar flooding and confines edema to the interstitium, where it is less likely to interfere with gas exchange

  17. Estimation of relative permeability and capillary pressure from mass imbibition experiments

    Science.gov (United States)

    Alyafei, Nayef; Blunt, Martin J.

    2018-05-01

    We perform spontaneous imbibition experiments on three carbonates - Estaillades, Ketton, and Portland - which are three quarry limestones that have very different pore structures and span wide range of permeability. We measure the mass of water imbibed in air saturated cores as a function of time under strongly water-wet conditions. Specifically, we perform co-current spontaneous experiments using a highly sensitive balance to measure the mass imbibed as a function of time for the three rocks. We use cores measuring 37 mm in diameter and three lengths of approximately 76 mm, 204 mm, and 290 mm. We show that the amount imbibed scales as the square root of time and find the parameter C, where the volume imbibed per unit cross-sectional area at time t is Ct1/2. We find higher C values for higher permeability rocks. Employing semi-analytical solutions for one-dimensional flow and using reasonable estimates of relative permeability and capillary pressure, we can match the experimental data. We finally discuss how, in combination with conventional measurements, we can use theoretical solutions and imbibition measurements to find or constrain relative permeability and capillary pressure.

  18. Effects of phase transformation of steam-water relative permeabilities

    Energy Technology Data Exchange (ETDEWEB)

    Verma, A.K.

    1986-03-01

    A combined theoretical and experimental study of steam-water relative permeabilities (RPs) was carried out. First, an experimental study of two-phase concurrent flow of steam and water was conducted and a set of RP curves was obtained. These curves were compared with semi-empirical and experimental results obtained by other investigators for two-phase, two-component flow (oil/gas; gas/water; gas/oil). It was found that while the wetting phase RPs were in good agreement, RPs for the steam phase were considerably higher than the non-wetting phase RPs in two-component systems. This enhancement of steam RP is attributed to phase transformation effects at the pore level in flow channels. The effects of phase transformation were studied theoretically. This study indicates that there are two separate mechanisms by which phase transformation affects RP curves: (1) Phase transformation is converging-diverging flow channels can cause an enhancement of steam phase RP. In a channel dominated by steam a fraction of the flowing steam condenses upstream from the constriction, depositing its latent heat of condensation. This heat is conducted through the solid grains around the pore throat, and evaporation takes place downstream from it. Therefore, for a given bulk flow quality; a smaller fraction of steam actually flows through the throat segments. This pore-level effect manifests itself as relative permeability enhancement on a macroscopic level; and (2) phase transformation along the interface of a stagnant phase and the phase flowing around it controls the irreducible phase saturation. Therefore, the irreducible phase saturation in steam-water flow will depend, among other factors, on the boundary conditions of the flow.

  19. A fractal model for predicting permeability and liquid water relative permeability in the gas diffusion layer (GDL) of PEMFCs

    Science.gov (United States)

    He, Guangli; Zhao, Zongchang; Ming, Pingwen; Abuliti, Abudula; Yin, Caoyong

    In this study, a fractal model is developed to predict the permeability and liquid water relative permeability of the GDL (TGP-H-120 carbon paper) in proton exchange membrane fuel cells (PEMFCs), based on the micrographs (by SEM, i.e. scanning electron microscope) of the TGP-H-120. Pore size distribution (PSD), maximum pore size, porosity, diameter of the carbon fiber, pore tortuosity, area dimension, hydrophilicity or hydrophobicity, the thickness of GDL and saturation are involved in this model. The model was validated by comparison between the predicted results and experimental data. The results indicate that the water relative permeability in the hydrophobicity case is much higher than in the hydrophilicity case. So, a hydrophobic carbon paper is preferred for efficient removal of liquid water from the cathode of PEMFCs.

  20. [Cognitive Function and Calcium. Structures and functions of Ca2+-permeable channels].

    Science.gov (United States)

    Kaneko, Shuji

    2015-02-01

    Calcium is essential for living organisms where the increase in intracellular Ca2+ concentration functions as a second messenger for many cellular processes including synaptic transmission and neural plasticity. The cytosolic concentration of Ca2+ is finely controlled by many Ca2+-permeable ion channels and transporters. The comprehensive view of their expression, function, and regulation will advance our understanding of neural and cognitive functions of Ca2+, which leads to the future drug discovery.

  1. Modeling of Multiphase with Respect to Low Interfacial Tension by Pseudo-Two-Phase Relative Permeability Functions Modélisation d'un écoulement polyphasique à faible tension interfaciale par des fonctions pseudo-biphasiques de perméabilité relative

    Directory of Open Access Journals (Sweden)

    Pusch G.

    2006-11-01

    Full Text Available A new 2-parameter desaturation function is introduced which offers a broader range of applicability to reservoir rock. Based on this function two-phase relative permeabilities are derived for oil phase and microemulsion flow. These functions are used to match a laboratory experiment by using surfactant flooding for a single surfactant system. Les auteurs présentent une nouvelle fonction de désaturation à deux paramètres qui offre une plus large gamme de possibilités d'application aux roches réservoir. On tire de cette fonction des perméabilités relatives biphasiques pour l'écoulement de la phase pétrole et d'une microémulsion. Ces fonctions sont utilisées pour reproduire une expérience de laboratoire avec injection de surfactant pour un seul système surfactant.

  2. Fatty acids are required for epidermal permeability barrier function.

    Science.gov (United States)

    Mao-Qiang, M; Elias, P M; Feingold, K R

    1993-08-01

    The permeability barrier is mediated by a mixture of ceramides, sterols, and free fatty acids arranged as extracellular lamellar bilayers in the stratum corneum. Whereas prior studies have shown that cholesterol and ceramides are required for normal barrier function, definitive evidence for the importance of nonessential fatty acids is not available. To determine whether epidermal fatty acid synthesis also is required for barrier homeostasis, we applied 5-(tetradecyloxy)-2-furancarboxylic acid (TOFA), an inhibitor of acetyl CoA carboxylase, after disruption of the barrier by acetone or tape stripping. TOFA inhibits epidermal fatty acid by approximately 50% and significantly delays barrier recovery. Moreover, coadministration of palmitate with TOFA normalizes barrier recovery, indicating that the delay is due to a deficiency in bulk fatty acids. Furthermore, TOFA treatment also delays the return of lipids to the stratum corneum and results in abnormalities in the structure of lamellar bodies, the organelle which delivers lipid to the stratum corneum. In addition, the organization of secreted lamellar body material into lamellar bilayers within the stratum corneum interstices is disrupted by TOFA treatment. Finally, these abnormalities in lamellar body and stratum corneum membrane structure are corrected by coapplication of palmitate with TOFA. These results demonstrate a requirement for bulk fatty acids in barrier homeostasis. Thus, inhibiting the epidermal synthesis of any of the three key lipids that form the extracellular, lipid-enriched membranes of the stratum corneum results in an impairment in barrier homeostasis.

  3. Cross-property relations and permeability estimation in model porous media

    International Nuclear Information System (INIS)

    Schwartz, L.M.; Martys, N.; Bentz, D.P.; Garboczi, E.J.; Torquato, S.

    1993-01-01

    Results from a numerical study examining cross-property relations linking fluid permeability to diffusive and electrical properties are presented. Numerical solutions of the Stokes equations in three-dimensional consolidated granular packings are employed to provide a basis of comparison between different permeability estimates. Estimates based on the Λ parameter (a length derived from electrical conduction) and on d c (a length derived from immiscible displacement) are found to be considerably more reliable than estimates based on rigorous permeability bounds related to pore space diffusion. We propose two hybrid relations based on diffusion which provide more accurate estimates than either of the rigorous permeability bounds

  4. Effect of age of permeable pavements on their infiltration function

    NARCIS (Netherlands)

    Boogaard, Floris; Lucke, Terry; Beecham, Simon

    This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been

  5. Effect of age of permeable pavements on their infiltration function

    NARCIS (Netherlands)

    Terry Lucke; ir. Floris Boogaard; Simon Beecham

    2013-01-01

    This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been

  6. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders

    Science.gov (United States)

    Kelly, John R.; Kennedy, Paul J.; Cryan, John F.; Dinan, Timothy G.; Clarke, Gerard; Hyland, Niall P.

    2015-01-01

    The emerging links between our gut microbiome and the central nervous system (CNS) are regarded as a paradigm shift in neuroscience with possible implications for not only understanding the pathophysiology of stress-related psychiatric disorders, but also their treatment. Thus the gut microbiome and its influence on host barrier function is positioned to be a critical node within the brain-gut axis. Mounting preclinical evidence broadly suggests that the gut microbiota can modulate brain development, function and behavior by immune, endocrine and neural pathways of the brain-gut-microbiota axis. Detailed mechanistic insights explaining these specific interactions are currently underdeveloped. However, the concept that a “leaky gut” may facilitate communication between the microbiota and these key signaling pathways has gained traction. Deficits in intestinal permeability may underpin the chronic low-grade inflammation observed in disorders such as depression and the gut microbiome plays a critical role in regulating intestinal permeability. In this review we will discuss the possible role played by the gut microbiota in maintaining intestinal barrier function and the CNS consequences when it becomes disrupted. We will draw on both clinical and preclinical evidence to support this concept as well as the key features of the gut microbiota which are necessary for normal intestinal barrier function. PMID:26528128

  7. Gas-liquid Relative Permeability Estimation in 2D Porous Media by Lattice Boltzmann Method: Low Viscosity Ratio 2D LBM Relative Permeability

    Directory of Open Access Journals (Sweden)

    Sadegh Mahmoudi

    2013-04-01

    Full Text Available This work is a primary achievement in studying the CO2 and N2–oil systems. To predict gas-liquid relative permeability curves, a Shan-Chen type multicomponent multiphase lattice Boltzmann model for two-phase flow through 2D porous media is developed. Periodic and bounce back boundary conditions are applied to the model with the Guo scheme for the external body force (i.e., the pressure gradient. The influence of relationship between cohesion and adsorption parameters and the interfacial tension values in Young's equation, pore structure (micro scan image derived porous media response is compared with corresponding porosity and permeability ideal sphere pack structure, and saturation distribution on relative permeability curves are studied with the aim to achieve the realistic stable condition for the simulation of gas-liquid systems with a low viscosity ratio.

  8. A new method for the experimental determination of three-phase relative permeabilities

    International Nuclear Information System (INIS)

    Perez Carrillo, Edgar Ricardo; Jose Francisco Zapata Arango; Santos Santos, Nicolas

    2008-01-01

    Petroleum reservoirs under primary, secondary or tertiary recovery processes usually experience simultaneous flow of three fluids phases (oil, water and gas). Reports on some mathematical models for calculating three-phase relative permeability are available in the Literature. Nevertheless, many of these models were designed based on certain experimental conditions and reservoir rocks and fluids. Therefore, special care has to be taken when applying them to specific reservoirs. At the laboratory level, three-phase relative permeability can be calculated using experimental unsteady-state or steady state methodologies. This paper proposes an unsteady-state methodology to evaluate three-phase relative permeability using the equipment available at the petrophysical analysis Laboratory of the Instituto Colombiano del Petroleo (ICP) of Ecopetrol S.A. Improvements to the equipment were effected in order to achieve accuracy in the unsteady-state measurement of three-phase relative permeability. The target of improvements was directed toward to the attainment of two objectives:1) the modification of the equipment to obtain more reliable experimental data and 2) the appropriate interpretation of the data obtained. Special attention was given to the differential pressure and uncertainty measurement in the determination of fluid saturation in the rock samples. Three experiments for three-phase relative permeability were conducted using a sample A and reservoir rock from the Colombian Foothills. Fluid tests included the utilization of synthetic brine, mineral oil, reservoir crude oil and nitrogen. Two runs were conducted at the laboratory conditions while one run was conducted at reservoir conditions. Experimental results of these tests were compared using 16 mathematical models of three-phase relative permeability. For the three-phase relative permeability to oil, the best correlations between experimental data and tests using Blunt, Hustad Hasen, and Baker's models were

  9. The hydraulic permeability of blood clots as a function of fibrin and platelet density.

    Science.gov (United States)

    Wufsus, A R; Macera, N E; Neeves, K B

    2013-04-16

    Interstitial fluid flow within blood clots is a biophysical mechanism that regulates clot growth and dissolution. Assuming that a clot can be modeled as a porous medium, the physical property that dictates interstitial fluid flow is the hydraulic permeability. The objective of this study was to bound the possible values of the hydraulic permeability in clots formed in vivo and present relationships that can be used to estimate clot permeability as a function of composition. A series of clots with known densities of fibrin and platelets, the two major components of a clot, were formed under static conditions. The permeability was calculated by measuring the interstitial fluid velocity through the clots at a constant pressure gradient. Fibrin gels formed with a fiber volume fraction of 0.02-0.54 had permeabilities of 1.2 × 10(-1)-1.5 × 10(-4)μm(2). Platelet-rich clots with a platelet volume fraction of 0.01-0.61 and a fibrin volume fraction of 0.03 had permeabilities over a range of 1.1 × 10(-2)-1.5 × 10(-5)μm(2). The permeability of fibrin gels and of clots with platelet volume fraction of platelet volume fraction of >0.2 were modeled as a Brinkman medium of coarse solids (platelets) embedded in a mesh of fine fibers (fibrin). Our data suggest that the permeability of clots formed in vivo can vary by up to five orders of magnitude, with pore sizes that range from 4 to 350 nm. These findings have important implications for the transport of coagulation zymogens/enzymes in the interstitial spaces during clot formation, as well as the design of fibrinolytic drug delivery strategies. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  10. Laboratory-scale measurements of effective relative permeability for layered sands

    Energy Technology Data Exchange (ETDEWEB)

    Butts, M.G.; Korsgaard, S.

    1996-12-31

    Predictions of the impact of remediation or the extent of contamination resulting from spills of gasoline, solvents and other petroleum products, must often be made in complex geological environments. Such problems can be treated by introducing the concept of effective parameters that incorporate the effects of soil layering or other heterogeneities into a large-scale flow description. Studies that derive effective multiphase parameters are few, and approximations are required to treat the non-linear multiphase flow equations. The purpose of this study is to measure effective relative permeabilities for well-defined multi-layered soils at the laboratory scale. Relative permeabilities were determined for homogeneous and layered, unconsolidated sands using the method of Jones and Roszelle (1978). The experimental data show that endpoint relative permeabilities are important in defining the shape of the relative permeability curves, but these cannot be predicted by estimation methods base on capillary pressure data. The most significant feature of the measured effective relative permeability curves is that the entrapped (residual) oil saturation is significantly larger than the residual saturation of the individual layers. This observation agrees with previous theoretical predictions of large-scale entrapment Butts, 1993 and (1995). Enhanced entrapment in heterogeneous soils has several important implications for spill remediation, for example, the reduced efficiency of direct recovery. (au) 17 refs.

  11. Laboratory-scale measurements of effective relative permeability for layered sands

    International Nuclear Information System (INIS)

    Butts, M.G.; Korsgaard, S.

    1996-01-01

    Predictions of the impact of remediation or the extent of contamination resulting from spills of gasoline, solvents and other petroleum products, must often be made in complex geological environments. Such problems can be treated by introducing the concept of effective parameters that incorporate the effects of soil layering or other heterogeneities into a large-scale flow description. Studies that derive effective multiphase parameters are few, and approximations are required to treat the non-linear multiphase flow equations. The purpose of this study is to measure effective relative permeabilities for well-defined multi-layered soils at the laboratory scale. Relative permeabilities were determined for homogeneous and layered, unconsolidated sands using the method of Jones and Roszelle (1978). The experimental data show that endpoint relative permeabilities are important in defining the shape of the relative permeability curves, but these cannot be predicted by estimation methods base on capillary pressure data. The most significant feature of the measured effective relative permeability curves is that the entrapped (residual) oil saturation is significantly larger than the residual saturation of the individual layers. This observation agrees with previous theoretical predictions of large-scale entrapment Butts, 1993 and (1995). Enhanced entrapment in heterogeneous soils has several important implications for spill remediation, for example, the reduced efficiency of direct recovery. (au) 17 refs

  12. Permeability of skin and oral mucosa to water and horseradish peroxidase as related to the thickness of the permeability barrier

    International Nuclear Information System (INIS)

    Squier, C.A.; Hall, B.K.

    1985-01-01

    The permeability of porcine skin and keratinized and nonkeratinized oral mucosa to tritium-labeled water and horseradish peroxidase (HRPO) was determined using perfusion chambers. Small blocks from each tissue were also incubated with HRPO and the extent of penetration visualized microscopically; this enabled measurements to be made of the thickness of the permeability barrier to this water-soluble tracer. Results obtained after inverting the oral mucosa in the chambers or adding metabolic inhibitors indicated that both compounds diffuse across the tissue. The permeability constants derived directly in the study showed that skin was less permeable than oral mucosa and that the floor of the mouth was significantly more permeable than all other regions. When these constants were normalized in terms of a standard permeability barrier thickness and the different tissues compared, the values obtained for skin were again less than those of the oral regions but, of these, the buccal mucosa was significantly higher. The difference in permeability between epidermis and keratinized oral epithelium may be due to differences in the volume density of membrane-coating granules known to exist between the tissues; differences between the oral mucosal regions may reflect differences in the nature of the intercellular barrier material

  13. Theoretical Insight Into the Empirical Tortuosity-Connectivity Factor in the Burdine-Brooks-Corey Water Relative Permeability Model

    Science.gov (United States)

    Ghanbarian, Behzad; Ioannidis, Marios A.; Hunt, Allen G.

    2017-12-01

    A model commonly applied to the estimation of water relative permeability krw in porous media is the Burdine-Brooks-Corey model, which relies on a simplified picture of pores as a bundle of noninterconnected capillary tubes. In this model, the empirical tortuosity-connectivity factor is assumed to be a power law function of effective saturation with an exponent (μ) commonly set equal to 2 in the literature. Invoking critical path analysis and using percolation theory, we relate the tortuosity-connectivity exponent μ to the critical scaling exponent t of percolation that characterizes the power law behavior of the saturation-dependent electrical conductivity of porous media. We also discuss the cause of the nonuniversality of μ in terms of the nonuniversality of t and compare model estimations with water relative permeability from experiments. The comparison supports determining μ from the electrical conductivity scaling exponent t, but also highlights limitations of the model.

  14. Flow visualization and relative permeability measurements in rough-walled fractures

    International Nuclear Information System (INIS)

    Persoff, P.; Pruess, K.

    1993-01-01

    Two-phase (gas-liquid) flow experiments were done in a natural rock fracture and transparent replicas of natural fractures. Liquid was injected at constant volume flow rate, and gas was injected at either constant mass flow rate or constant pressure. When gas was injected at constant mass flow rate, the gas inlet pressure, and inlet and outlet capillary pressures, generally did not reach steady state but cycled irregularly. Flow visualization showed that this cycling was due to repeated blocking and unblocking of gas flow paths by liquid. Relative permeabilities calculated from flow rate and pressure data show that the sum of the relative permeabilities of the two phases is much less than 1, indicating that each phase interferes strongly with the flow of the other. Comparison of the relative permeability curves with typical curves for porous media (Corey curves) show that the phase interference is stronger in fractures than in typical porous media

  15. Mathematic modeling of the method of measurement relative dielectric permeability

    Science.gov (United States)

    Plotnikova, I. V.; Chicherina, N. V.; Stepanov, A. B.

    2018-05-01

    The method of measuring relative permittivity’s and the position of the interface between layers of a liquid medium is considered in the article. An electric capacitor is a system consisting of two conductors that are separated by a dielectric layer. It is mathematically proven that at any given time it is possible to obtain the values of the relative permittivity in the layers of the liquid medium and to determine the level of the interface between the layers of the two-layer liquid. The estimation of measurement errors is made.

  16. Use of digital image analysis to estimate fluid permeability of porous materials: Application of two-point correlation functions

    International Nuclear Information System (INIS)

    Berryman, J.G.; Blair, S.C.

    1986-01-01

    Scanning electron microscope images of cross sections of several porous specimens have been digitized and analyzed using image processing techniques. The porosity and specific surface area may be estimated directly from measured two-point spatial correlation functions. The measured values of porosity and image specific surface were combined with known values of electrical formation factors to estimate fluid permeability using one version of the Kozeny-Carman empirical relation. For glass bead samples with measured permeability values in the range of a few darcies, our estimates agree well ( +- 10--20%) with the measurements. For samples of Ironton-Galesville sandstone with a permeability in the range of hundreds of millidarcies, our best results agree with the laboratory measurements again within about 20%. For Berea sandstone with still lower permeability (tens of millidarcies), our predictions from the images agree within 10--30%. Best results for the sandstones were obtained by using the porosities obtained at magnifications of about 100 x (since less resolution and better statistics are required) and the image specific surface obtained at magnifications of about 500 x (since greater resolution is required)

  17. INTESTINAL PERMEABILITY IN PATIENTS WITH CELIAC-DISEASE AND RELATIVES OF PATIENTS WITH CELIAC-DISEASE

    NARCIS (Netherlands)

    van Elburg, R. M.; Uil, J. J.; Mulder, C. J.; Heymans, H. S.

    1993-01-01

    The functional integrity of the small bowel is impaired in coeliac disease. Intestinal permeability, as measured by the sugar absorption test probably reflects this phenomenon. In the sugar absorption test a solution of lactulose and mannitol was given to the fasting patient and the

  18. INTESTINAL PERMEABILITY IN PATIENTS WITH CELIAC-DISEASE AND RELATIVES OF PATIENTS WITH CELIAC-DISEASE

    NARCIS (Netherlands)

    VANELBURG, RM; UIL, JJ; MULDER, CJJ; HEYMANS, HSA

    The functional integrity of the small bowel is impaired in coeliac disease. Intestinal permeability, as measured by the sugar absorption test probably reflects this phenomenon. In the sugar absorption test a solution of lactulose and mannitol was given to the fasting patient and the

  19. Functional Programming With Relations

    OpenAIRE

    Hutton, Graham

    1991-01-01

    While programming in a relational framework has much to offer over the functional style in terms of expressiveness, computing with relations is less efficient, and more semantically troublesome. In this paper we propose a novel blend of the functional and relational styles. We identify a class of "causal relations", which inherit some of the bi-directionality properties of relations, but retain the efficiency and semantic foundations of the functional style.

  20. Relative permeability of fractured wellbore cement: an experimental investigation using electrical resistivity monitoring for moisture content

    Science.gov (United States)

    Um, W.; Rod, K. A.; Strickland, C. E.

    2016-12-01

    Permeability is a critical parameter needed to understand flow in subsurface environments; it is particularly important in deep subsurface reservoirs where multiphase fluid flow is common, such as carbon sequestration and geothermal reservoirs. Cement is used in the annulus of wellbores due to its low permeable properties to seal aquifers, reducing leaks to adjacent strata. Extreme subsurface environments of CO2 storage and geothermal production conditions will eventually reduce the cement integrity, propagating fracture networks and increasing the permeability for air and/or water. To date, there have been no reproducible experimental investigations of relative permeability in fractured wellbore cement published. To address this gap, we conducted a series of experiments using fractured Portland cement monoliths with increasing fracture networks. The monolith cylinder sides were jacketed with heavy-duty moisture-seal heat-shrink tubing, then fractured using shear force applied via a hydraulic press. Fractures were generated with different severity for each of three monoliths. Stainless steel endcaps were fixed to the monoliths using the same shrink-wrapped jacket. Fracture characteristics were determined using X-ray microtomography and image analysis. Flow controllers were used to control flow of water and air to supply continuous water or water plus air, both of which were delivered through the influent end cap. Effluent air flow was monitored using a flow meter, and water flow was measured gravimetrically. To monitor the effective saturation of the fractures, a RCON2 concrete bulk electrical resistivity test device was attached across both endcaps and a 0.1M NaNO3 brine was used as the transport fluid to improve resistivity measurements. Water content correlated to resistivity measurements with a r2 > 0.96. Data from the experiments was evaluated using two relative permeability models, the Corey-curve, often used for modeling relative permeability in porous media

  1. 3D numerical surface charge model including relative permeability : the general theory

    NARCIS (Netherlands)

    Casteren, van D.T.E.H.; Paulides, J.J.H.; Lomonova, E.A.

    2014-01-01

    One of the still "open" issues within low-frequency magnetics is the inclusion of µr in the calculations using the magnetic charge method. In this paper a new iterative method to take the relative permeability into account is investigated. Results show that the model accurately accounts for the

  2. Evaluation of methods for measuring relative permeability of anhydride from the Salado Formation: Sensitivity analysis and data reduction

    International Nuclear Information System (INIS)

    Christiansen, R.L.; Kalbus, J.S.

    1997-05-01

    This report documents, demonstrates, evaluates, and provides theoretical justification for methods used to convert experimental data into relative permeability relationships. The report facilities accurate determination of relative permeabilities of anhydride rock samples from the Salado Formation at the Waste Isolation Pilot Plant (WIPP). Relative permeability characteristic curves are necessary for WIPP Performance Assessment (PA) predictions of the potential for flow of waste-generated gas from the repository and brine flow into repository. This report follows Christiansen and Howarth (1995), a comprehensive literature review of methods for measuring relative permeability. It focuses on unsteady-state experiments and describes five methods for obtaining relative permeability relationships from unsteady-state experiments. Unsteady-state experimental methods were recommended for relative permeability measurements of low-permeability anhydrite rock samples form the Salado Formation because these tests produce accurate relative permeability information and take significantly less time to complete than steady-state tests. Five methods for obtaining relative permeability relationships from unsteady-state experiments are described: the Welge method, the Johnson-Bossler-Naumann method, the Jones-Roszelle method, the Ramakrishnan-Cappiello method, and the Hagoort method. A summary, an example of the calculations, and a theoretical justification are provided for each of the five methods. Displacements in porous media are numerically simulated for the calculation examples. The simulated product data were processed using the methods, and the relative permeabilities obtained were compared with those input to the numerical model. A variety of operating conditions were simulated to show sensitivity of production behavior to rock-fluid properties

  3. Measurement of choroid plexus perfusion using dynamic susceptibility MR imaging: capillary permeability and age-related changes

    Energy Technology Data Exchange (ETDEWEB)

    Bouzerar, Roger; Chaarani, Bader; Baledent, Olivier [University Hospital, Image Processing Department, Amiens (France); Gondry-Jouet, Catherine [University Hospital, Radiology Department, Amiens (France); Zmudka, Jadwiga [University Hospital, Geriatric Unit, Amiens (France)

    2013-12-15

    The cerebrospinal fluid (CSF) plays a major role in the physiology of the central nervous system. The continuous turnover of CSF is mainly attributed to the highly vascularized choroid plexus (CP) located in the cerebral ventricles which represent a complex interface between blood and CSF. We propose a method for evaluating CP functionality in vivo using perfusion MR imaging and establish the age-related changes of associated parameters. Fifteen patients with small intracranial tumors were retrospectively studied. MR Imaging was performed on a 3T MR Scanner. Gradient-echo echo planar images were acquired after bolus injection of gadolinium-based contrast agent (CA). The software developed used the combined T1- and T2-effects. The decomposition of the relaxivity signals enables the calculation of the CP capillary permeability (K{sub 2}). The relative cerebral blood volume (rCBV), mean transit time (MTT), and signal slope decrease (SSD) were also calculated. The mean permeability K{sub 2} of the extracted CP was 0.033+/-0.18 s{sup -1}. K{sub 2} and SSD significantly decreased with subject's age whereas MTT significantly increased with subject's age. No significant correlation was found for age-related changes in rCBV and rCBF. The decrease in CP permeability is in line with the age-related changes in CSF secretion observed in animals. The MTT increase indicates significant structural changes corroborated by microscopy studies in animals or humans. Overall, DSC MR-perfusion enables an in vivo evaluation of the hemodynamic state of CP. Clinical applications such as neurodegenerative diseases could be considered thanks to specific functional studies of CP. (orig.)

  4. Plasma proteins in a standardised skin mini-erosion (I: permeability changes as a function of time

    Directory of Open Access Journals (Sweden)

    Ryan Terence J

    2002-02-01

    Full Text Available Abstract Background A standardised technique using a suction-induced mini-erosion that allows serial sampling of dermal interstitial fluid (IF for 5 to 6 days has been described. In the present study, we studied permeability changes as a function of time. Methods We examined IF concentrations of total protein concentration and the concentration of insulin (6.6 kDa, prealbumin (55 kDa, albumin (66 kDa, transferrin (80 kDa, IgG (150 kDa and alpha-2-macroglobulin (720 kDa as a function of time, using an extraction pressure of 200 mmHg below atmospheric. Results At 0 h after forming the erosion, mean total IF protein content (relative to plasma was 26 ± 13% (SD. For the individual proteins, the relative mean concentrations were 65 ± 36% for insulin, 48 ± 12% for albumin, 30 ± 19% for transferrin, 31 ± 15%for IgG and 19.5 ± 10% for alpha-2-macroglobulin. At 24 h, the total IF protein content was higher than at 0 h (56 ± 26% vs 26 ± 13%; p Conclusions The results indicate that fluid sampled at 0 h after forming the erosion represents dermal IF before the full onset of inflammation. From 24 h onward, the sampled fluid reflects a steady state of increased permeability induced by inflammation. This technique is promising as a tool for clinically sampling substances that are freely distributed in the body and as a model for studying inflammation and vascular permeability.

  5. Functions of public relations

    OpenAIRE

    Baranov G. V.

    2016-01-01

    the article reveals the importance of communication with the public in the implementation of human rights and the ideals of mankind; characterized by the specificity of public relations in the information culture of belief; PR functions are explained on the criterion of optimization of activity of social interactions on the basis of cultural ideals.

  6. The Effect of Wettability Heterogeneity on Relative Permeability of Two-Phase Flow in Porous Media: A Lattice Boltzmann Study

    Science.gov (United States)

    Zhao, Jianlin; Kang, Qinjun; Yao, Jun; Viswanathan, Hari; Pawar, Rajesh; Zhang, Lei; Sun, Hai

    2018-02-01

    Relative permeability is a critical parameter characterizing multiphase flow in porous media and it is strongly dependent on the wettability. In many situations, the porous media are nonuniformly wet. To investigate the effect of wettability heterogeneity on relative permeability of two-phase flow in porous media, a multi-relaxation-time color-gradient lattice Boltzmann model is adopted to simulate oil/water two-phase flow in porous media with different oil-wet solid fractions. For the water phase, when the water saturation is high, the relative permeability of water increases with the increase of oil-wet solid fraction under a constant water saturation. However, as the water saturation decreases to an intermediate value (about 0.4-0.7), the relative permeability of water in fractionally wet porous media could be lower than that in purely water-wet porous media, meaning additional flow resistance exists in the fractionally wet porous media. For the oil phase, similar phenomenon is observed. This phenomenon is mainly caused by the wettability-related microscale fluid distribution. According to both our simulation results and theoretical analysis, it is found that the relative permeability of two-phase flow in porous media is strongly related to three parameters: the fluid saturation, the specific interfacial length of fluid, and the fluid tortuosity in the flow direction. The relationship between the relative permeability and these parameters under different capillary numbers is explored in this paper.

  7. Impact of Three-Phase Relative Permeability and Hysteresis Models on Forecasts of Storage Associated With CO2-EOR

    Science.gov (United States)

    Jia, Wei; McPherson, Brian; Pan, Feng; Dai, Zhenxue; Moodie, Nathan; Xiao, Ting

    2018-02-01

    Geological CO2 sequestration in conjunction with enhanced oil recovery (CO2-EOR) includes complex multiphase flow processes compared to CO2 storage in deep saline aquifers. Two of the most important factors affecting multiphase flow in CO2-EOR are three-phase relative permeability and associated hysteresis, both of which are difficult to measure and are usually represented by numerical interpolation models. The purpose of this study is to improve understanding of (1) the relative impacts of different three-phase relative permeability models and hysteresis models on CO2 trapping mechanisms, and (2) uncertainty associated with these two factors. Four different three-phase relative permeability models and three hysteresis models were applied to simulations of an active CO2-EOR site, the SACROC unit located in western Texas. To eliminate possible bias of deterministic parameters, we utilized a sequential Gaussian simulation technique to generate 50 realizations to describe heterogeneity of porosity and permeability, based on data obtained from well logs and seismic survey. Simulation results of forecasted CO2 storage suggested that (1) the choice of three-phase relative permeability model and hysteresis model led to noticeable impacts on forecasted CO2 sequestration capacity; (2) impacts of three-phase relative permeability models and hysteresis models on CO2 trapping are small during the CO2-EOR injection period, and increase during the post-EOR CO2 injection period; (3) the specific choice of hysteresis model is more important relative to the choice of three-phase relative permeability model; and (4) using the recommended three-phase WAG (Water-Alternating-Gas) hysteresis model may increase the impact of three-phase relative permeability models and uncertainty due to heterogeneity.

  8. Intestinal Permeability: The Basics

    Directory of Open Access Journals (Sweden)

    Ingvar Bjarnason

    1995-01-01

    Full Text Available The authors review some of the more fundamental principles underlying the noninvasive assessment of intestinal permeability in humans, the choice of test markers and their analyses, and the practical aspects of test dose composition and how these can be changed to allow the specific assessment of regional permeability changes and other intestinal functions. The implications of increased intestinal permeability in the pathogenesis of human disease is discussed in relation to findings in patients with Crohn’s disease. A common feature of increased intestinal permeability is the development of a low grade enteropathy, and while quantitatively similar changes may be found in Crohn’s disease these seem to predict relapse of disease. Moreover, factors associated with relapse of Crohn’s disease have in common an action to increase intestinal permeability. While increased intestinal permeability does not seem to be important in the etiology of Crohn’s disease it may be a central mechanism in the clinical relapse of disease.

  9. Regional-Dependent Intestinal Permeability and BCS Classification: Elucidation of pH-Related Complexity in Rats Using Pseudoephedrine

    OpenAIRE

    Fairstein, Moran; Swissa, Rotem; Dahan, Arik

    2013-01-01

    Based on its lower Log P value relative to metoprolol, a marker for the low/high-permeability (Peff) class boundary, pseudoephedrine was provisionally classified as BCS low-permeability compound. On the other hand, following oral administration, pseudoephedrine fraction dose absorbed (Fabs) and systemic bioavailability approaches 100%. This represents a challenge to the generally recognized Peff–Fabs correlation. The purpose of this study was to elucidate the underlying mechanisms behind the ...

  10. Gut permeability is related to body weight, fatty liver disease, and insulin resistance in obese individuals undergoing weight reduction.

    Science.gov (United States)

    Damms-Machado, Antje; Louis, Sandrine; Schnitzer, Anna; Volynets, Valentina; Rings, Andreas; Basrai, Maryam; Bischoff, Stephan C

    2017-01-01

    Obesity and associated metabolic disorders are related to impairments of the intestinal barrier. We examined lactulose:mannitol (Lac:Man) permeability in obese individuals with and without liver steatosis undergoing a weight-reduction program to test whether an effective weight-loss program improves gut barrier function and whether obese patients with or without liver steatosis differ in this function. Twenty-seven adult, nondiabetic individuals [mean ± SD body mass index (BMI; in kg/m 2 ): 43.7 ± 5.2; 78% with moderate or severe liver steatosis] were included in the follow-up intervention study (n = 13 by month 12). All patients reduced their weight to a mean ± SD BMI of 36.4 ± 5.1 within 12 mo. We assessed barrier functions by the oral Lac:Man and the fecal zonulin tests. Insulin resistance was assessed by the homeostatic model assessment index (HOMA), and liver steatosis by sonography and the fatty liver index (FLI). The Lac:Man ratio and circulating interleukin (IL) 6 concentration decreased during intervention from 0.080 (95% CI: 0.073, 0.093) to 0.027 (95% CI: 0.024, 0.034; P < 0.001) and from 4.2 ± 1.4 to 2.8 ± 1.6 pg/mL (P < 0.01), respectively. At study start, the Lac:Man ratio was higher in patients with moderate or severe steatosis than in those without any steatosis (P < 0.001). The Lac:Man ratio tended to correlate with HOMA (ρ = 0.55, P = 0.052), which correlated with FLI (ρ = 0.75, P < 0.01). A multiple-regression analysis led to a final model explaining FLI best through BMI, waist circumference, and the Lac:Man ratio. Intestinal permeability is increased in obese patients with steatosis compared with obese patients without. The increased permeability fell to within the previously reported normal range after weight reduction. The data suggest that a leaky gut barrier is linked with liver steatosis and could be a new target for future steatosis therapies. This trial was registered at clinicaltrials.gov as NCT01344525. © 2017 American Society

  11. Intestinal permeability of 51Cr-labelled ethylenediaminetetraacetic acid in patients with Crohn's disease and their healthy relatives

    International Nuclear Information System (INIS)

    Ainsworth, M.; Eriksen, J.; Rasmussen, J.W.; Muckadell, O.B.S. de

    1989-01-01

    An increased intestinal permeability has been proposed as an aetiologic factor in Crohn's disease. The 24-h urinary excretion of 100 μCi 51 Cr-labelled ethylenediaminetetraacetic acid (EDTA) was used to test the permeability in 15 patients with Crohn's disease and in 20 healthy first-degree relatives, who were known to have a genetic predisposition to inflammatory bowel disease. Twenty-eight healthy persons not related to patients with inflammatory bowel disease served as control material. The 51 Cr-EDTA excretion of the relatives was not significantly higher than that of the controls, whereas patients with Crohn's disease had a significantly higher excretion than both the relatives and the controls. Among patients the increased excretion was found only if the small intestine was involved. It is concluded that 1) as a group, patient with Crohn's disease in the small intestine have an increased intestinal permeability, in contrast to their healthy relatives, who have a normal permeability; 2) a considerable overlap of the results of the 51 Cr-EDTA test was found between the groups studied, and the test is not suitable for evaluating individual patients; 3) the results do not support the hypothesis of an increase in intestinal permeability as an aetiologic factor in Crohn's disease. 29 refs

  12. Sensitivity Analysis of Interfacial Tension on Saturation and Relative Permeability Model Predictions

    KAUST Repository

    Abdallah, Wael; Zhao, Weishu; Gmira, Ahmed; Negara, Ardiansyah; Buiting, Jan

    2011-01-01

    Interfacial tension (IFT) measurements of Dodecane/brine systems at different concentrations and Dodecane/deionized water subject to different Dodecane purification cycles were taken over extended durations at room temperature and pressure to investigate the impact of aging. When a fresh droplet was formed, a sharp drop in IFT was observed assumed to be a result of intrinsic impurity adsorption at the interface. The subsequent measurements exhibited a prolonged equilibration period consistent with diffusion from the bulk phase to the interface. Our results indicate that minute amounts of impurities present in experimental chemical fluids "used as received" have a drastic impact on the properties of the interface. Initial and equilibrium IFT are shown to be dramatically different, therefore it is important to be cautious of utilizing IFT values in numerical models. The study demonstrates the impact these variations in IFT have on relative permeability relationships by adopting a simple pore network model simulation.

  13. Sensitivity Analysis of Interfacial Tension on Saturation and Relative Permeability Model Predictions

    KAUST Repository

    Abdallah, Wael

    2011-05-18

    Interfacial tension (IFT) measurements of Dodecane/brine systems at different concentrations and Dodecane/deionized water subject to different Dodecane purification cycles were taken over extended durations at room temperature and pressure to investigate the impact of aging. When a fresh droplet was formed, a sharp drop in IFT was observed assumed to be a result of intrinsic impurity adsorption at the interface. The subsequent measurements exhibited a prolonged equilibration period consistent with diffusion from the bulk phase to the interface. Our results indicate that minute amounts of impurities present in experimental chemical fluids "used as received" have a drastic impact on the properties of the interface. Initial and equilibrium IFT are shown to be dramatically different, therefore it is important to be cautious of utilizing IFT values in numerical models. The study demonstrates the impact these variations in IFT have on relative permeability relationships by adopting a simple pore network model simulation.

  14. Regional-dependent intestinal permeability and BCS classification: elucidation of pH-related complexity in rats using pseudoephedrine.

    Science.gov (United States)

    Fairstein, Moran; Swissa, Rotem; Dahan, Arik

    2013-04-01

    Based on its lower Log P value relative to metoprolol, a marker for the low/high-permeability (P(eff)) class boundary, pseudoephedrine was provisionally classified as BCS low-permeability compound. On the other hand, following oral administration, pseudoephedrine fraction dose absorbed (F(abs)) and systemic bioavailability approaches 100%. This represents a challenge to the generally recognized P(eff)-F(abs) correlation. The purpose of this study was to elucidate the underlying mechanisms behind the confusion in pseudoephedrine's BCS classification. Pseudoephedrine's BCS solubility class was determined, and its physicochemical properties and intestinal permeability were thoroughly investigated, both in vitro and in vivo in rats, considering the complexity of the whole of the small intestine. Pseudoephedrine was found to be unequivocally a high-solubility compound. All of the permeability studies revealed similar phenomenon; at any given intestinal segment/pH, the permeability of metoprolol was higher than that of pseudoephedrine, however, as the intestinal region becomes progressively distal, and the pH gradually increases, pseudoephedrine's permeability rises above that of metoprolol in the former segment. This unique permeability pattern likely explains pseudoephedrine's complete absorption. In conclusion, pseudoephedrine is a BCS Class I compound; no discrepancy between P(eff) and F(abs) is involved in its absorption. Rather, it reflects the complexity behind P(eff) when considering the whole of the intestine. We propose to allow high-permeability classification to drugs with P(eff) that matches/exceeds the low/high class benchmark anywhere throughout the intestinal tract and not restricted necessarily to the jejunum.

  15. Improving the performance of water desalination through ultra-permeable functionalized nanoporous graphene oxide membrane

    Science.gov (United States)

    Hosseini, Mostafa; Azamat, Jafar; Erfan-Niya, Hamid

    2018-01-01

    Molecular dynamics simulations were performed to investigate the water desalination performance of nanoporous graphene oxide (NPGO) membranes. The simulated systems consist of a NPGO as a membrane with a functionalized pore in its center immersed in an aqueous ionic solution and a graphene sheet as a barrier. The considered NPGO membranes are involved four types of pore with different size and chemistry. The results indicated that the NPGO membrane has effective efficiency in salt rejection as well as high performance in water flux. For all types of pore with the radius size of 2.9-4.5 Å, the NPGO shows salt rejection of >89%. Functional groups on the surface and edge of pores have a great effect on water flux. To precisely understand the effect of functional groups on the surface of nanostructured membranes, nanoporous graphene was simulated under the same condition for comparison. Hydrophilic groups on the surface make the NPGO as an ultra-permeable membrane. As a result, the obtained water flux for NPGO was about 77% greater than graphene. Also, it was found that the water flux of NPGO is 2-5 orders of magnitude greater than other existing reverse osmosis membranes. Therefore, the investigated systems can be recommended as a model for the water desalination.

  16. Enhanced Neuroplasticity by the Metabolic Enhancer Piracetam Associated with Improved Mitochondrial Dynamics and Altered Permeability Transition Pore Function

    Directory of Open Access Journals (Sweden)

    Carola Stockburger

    2016-01-01

    Full Text Available The mitochondrial cascade hypothesis of dementia assumes mitochondrial dysfunction leading to reduced energy supply, impaired neuroplasticity, and finally cell death as one major pathomechanism underlying the continuum from brain aging over mild cognitive impairment to initial and advanced late onset Alzheimer’s disease. Accordingly, improving mitochondrial function has become an important strategy to treat the early stages of this continuum. The metabolic enhancer piracetam has been proposed as possible prototype for those compounds by increasing impaired mitochondrial function and related aspects like mechanisms of neuroplasticity. We here report that piracetam at therapeutically relevant concentrations improves neuritogenesis in the human cell line SH-SY5Y over conditions mirroring the whole spectrum of age-associated cognitive decline. These effects go parallel with improvement of impaired mitochondrial dynamics shifting back fission and fusion balance to the energetically more favorable fusion site. Impaired fission and fusion balance can also be induced by a reduction of the mitochondrial permeability transition pore (mPTP function as atractyloside which indicates the mPTP has similar effects on mitochondrial dynamics. These changes are also reduced by piracetam. These findings suggest the mPTP as an important target for the beneficial effects of piracetam on mitochondrial function.

  17. Enhanced Neuroplasticity by the Metabolic Enhancer Piracetam Associated with Improved Mitochondrial Dynamics and Altered Permeability Transition Pore Function.

    Science.gov (United States)

    Stockburger, Carola; Miano, Davide; Pallas, Thea; Friedland, Kristina; Müller, Walter E

    2016-01-01

    The mitochondrial cascade hypothesis of dementia assumes mitochondrial dysfunction leading to reduced energy supply, impaired neuroplasticity, and finally cell death as one major pathomechanism underlying the continuum from brain aging over mild cognitive impairment to initial and advanced late onset Alzheimer's disease. Accordingly, improving mitochondrial function has become an important strategy to treat the early stages of this continuum. The metabolic enhancer piracetam has been proposed as possible prototype for those compounds by increasing impaired mitochondrial function and related aspects like mechanisms of neuroplasticity. We here report that piracetam at therapeutically relevant concentrations improves neuritogenesis in the human cell line SH-SY5Y over conditions mirroring the whole spectrum of age-associated cognitive decline. These effects go parallel with improvement of impaired mitochondrial dynamics shifting back fission and fusion balance to the energetically more favorable fusion site. Impaired fission and fusion balance can also be induced by a reduction of the mitochondrial permeability transition pore (mPTP) function as atractyloside which indicates the mPTP has similar effects on mitochondrial dynamics. These changes are also reduced by piracetam. These findings suggest the mPTP as an important target for the beneficial effects of piracetam on mitochondrial function.

  18. Experimental study of heavy oil-water flow structure effects on relative permeabilities in a fracture filled with heavy oil

    Energy Technology Data Exchange (ETDEWEB)

    Shad, S.; Gates, I.D.; Maini, B.B. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering]|[Alberta Ingenuity Centre for In Situ Energy, Edmonton, AB (Canada)

    2008-10-15

    An experimental apparatus was used to investigate the flow of water in the presence of heavy oil within a smooth-walled fracture. Different flow patterns were investigated under a variety of flow conditions. Results of the experiments were used to determine the accuracy of VC, Corey, and Shad and Gates models designed to represent the behaviour of oil wet systems. The relative permeability concept was used to describe the behaviour of multiple phases flowing through porous media. A smooth-walled plexiglass Hele-Shaw cell was used to visualize oil and water flow. Changes in flow rates led to different flow regimes. The experiment demonstrated that water flowed co-currently in the form of droplets or slugs. Decreases in the oil flow rate enlarged the size of the water droplets as well as the velocity, until eventually the droplets coalesced and became water slugs. Droplet appearance or disappearance directly impacted the oil and water saturation levels. Changes in fluid saturation altered the pressure gradient. Darcy's law for the 2 liquid phases were used to calculate relative permeability curves. The study showed that at low water saturation, oil relative permeability reached as high as 2.5, while water relative permeability was lower than unity. In the presence of a continuous water channel, water drops formed in oil, and the velocity of the drops was lower than their velocity under a discontinuous water flow regime. It was concluded that the Shad and Gates model overestimated oil relative permeability and underestimated water relative permeability. 38 refs., 2 tabs., 9 figs.

  19. A casting and imaging technique for determining void geometry and relative permeability behavior of a single fracture specimen

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B.L.; Pruess, K.; Persoff, P.

    1990-01-01

    A casting technique has been developed for making translucent replicas of the void space of natural rock fractures. Attenuation of light shined through the cast combined with digital image analysis provides a pointwise definition of fracture apertures. The technique has been applied to a fracture specimen from Dixie Valley, Nevada, and the measured void space geometry has been used to develop theoretical predictions of two-phase relative permeability. A strong anisotropy in relative permeabilities has been found, which is caused by highly anisotropic spatial correlations among fracture apertures. 16 refs., 6 figs.

  20. The effect of pore-scale geometry and wettability on two-phase relative permeabilities within elementary cells

    Science.gov (United States)

    Bianchi Janetti, Emanuela; Riva, Monica; Guadagnini, Alberto

    2017-04-01

    We study the relative role of the complex pore space geometry and wettability of the solid matrix on the quantification of relative permeabilities characterizing steady state immiscible two-phase flow in porous media. We do so by considering elementary cells, which are typically employed in upscaling frameworks based on, e.g., homogenization or volume averaging. In this context one typically relies on the solution of pore-scale physics at a scale which is much smaller than that of an investigated porous system. Pressure-driven two-phase flow following simultaneous co-current injection of water and oil is numerically solved for a suite of regular and stochastically generated two-dimensional explicit elementary cells with fixed porosity and sharing main topological/morphological features. We show that relative permeabilities of the randomly generated elementary cells are significantly influenced by the formation of preferential percolation paths (principal pathways), giving rise to a strongly nonuniform distribution of fluid fluxes. These pathways are a result of the spatially variable resistance that the random pore structures exert on the fluid. The overall effect on relative permeabilities of the diverse organization of principal pathways, as driven by a given random realization at the scale of the unit cell, is significantly larger than that of the wettability of the host rock. In contrast to what can be observed for the random cells analyzed, relative permeabilities of regular cells display a clear trend with contact angle at the investigated scale. Our findings suggest the need to perform systematic upscaling studies in a stochastic context, to propagate the effects of uncertain pore space geometries to a probabilistic description of relative permeability curves at the continuum scale.

  1. Compositional and Relative Permeability Hysteresis Effects on Near-Miscible WAG

    DEFF Research Database (Denmark)

    Christensen, Jes Reimer; Stenby, Erling Halfdan; Skauge, Arne

    1998-01-01

    Evaluation of compositional effects and fluid flow description on near-miscible (water-alternating-gas) WAG modeling have been studied for a North Sea oil field starting production in 1998. A sector model with four wells was applied to simulate a heterogeneous sandstone reservoir, and a compositi......Evaluation of compositional effects and fluid flow description on near-miscible (water-alternating-gas) WAG modeling have been studied for a North Sea oil field starting production in 1998. A sector model with four wells was applied to simulate a heterogeneous sandstone reservoir......, and a compositional model was used to compare different production strategies e.g. waterflooding and a near-miscible (WAG) injection. In the WAG scheme both dry and wet (rich) hydrocarbon gases have been considered for injection. The phase behaviour was quantified by comparing the performance of the different...... injection gases. Result obtained shows the WAG injection gives improved recovery compared to water injection, due to better sweep and lower residual oil saturation. Simulations with and without relative permeability hysteresis (two-phase model) were compared. The effect of trapped gas on oil recovery does...

  2. Study of pressure drop, void fraction and relative permeabilities of two phase flow through porous media

    International Nuclear Information System (INIS)

    Chu, W.; Dhir, V.K.; Marshall, J.

    1983-01-01

    An experimental investigation of two phase flow through porous layers formed of non-heated glass particles (nominal diameter 1 to 6 mm) has been made. Particulate bed depths of 30 cm and 70 cm were used. The effect of particle size, particle size distribution and bed porosity on void fraction and pressure drop through a particulate bed formed in a cylindrical test section has been investigated. The superficial velocity of liquid (water) is varied from 1.83 to 18.3 mm/s while the superficial velocity of gas (air) is varied from 0 to 68.4 mm/s. These superficial velocities were chosen so that pressure drop and void fraction measurement could be made for the porous layer in fixed and fluidized states. A model based on drift flux approach has been developed for the void fraction. Using the two phase friction pressure drop data, the relative permeabilities of the two phases have been concluded with void fraction. The void fraction and two phase friction pressure gradient in beds composed of mixtures of spherical particles as well as sharps of different nominal sizes have also been examined. It is found that the models for single size particles are also applicable to mixtures of particles if a mean particle diameter for the mixture is defined

  3. Tomographic evidence for enhanced fracturing and permeability within the relatively aseismic Nemaha Fault Zone, Oklahoma

    Science.gov (United States)

    Stevens, N. T.; Keranen, K. M.; Lambert, C.

    2017-12-01

    Recent earthquakes in north central Oklahoma are dominantly hosted on unmapped basement faults away from and outside of the largest regional structure, the Nemaha Fault Zone (NFZ) [Lambert, 2016]. The NFZ itself remains largely aseismic, despite the presence of disposal wells and numerous faults. Here we present results from double-difference tomography using TomoDD [Zhang and Thurber, 2003] for the NFZ and the surrounding region, utilizing a seismic catalog of over 10,000 local events acquired by 144 seismic stations deployed between 2013 and 2017. Inversion results for shallow crustal depth, beneath the 2-3 km sedimentary cover, show compressional wavespeeds (Vp) of >6 km/sec and shear wavespeeds (Vs) >4 km/sec outside the NFZ, consistent with crystalline rock. Along the western margin of the NFZ, both Vp and Vs are reduced, and Vp/Vs gradients parallel the trend of major faults, suggesting enhanced fault density and potentially enhanced fluid pressure within the study region. Enhanced fracture density within the NFZ, and associated permeability enhancement, could reduce the effect of regional fluid pressurization from injection wells, contributing to the relative aseismicity of the NFZ.

  4. Relative permeabilities of supercritical CO2 and brine in carbon sequestration by a two-phase lattice Boltzmann method

    Science.gov (United States)

    Xie, Jian.-Fei.; He, S.; Zu, Y. Q.; Lamy-Chappuis, B.; Yardley, B. W. D.

    2017-08-01

    In this paper, the migration of supercritical carbon dioxide (CO2) in realistic sandstone rocks under conditions of saline aquifers, with applications to the carbon geological storage, has been investigated by a two-phase lattice Boltzmann method (LBM). Firstly the digital images of sandstone rocks were reproduced utilizing the X-ray computed microtomography (micro-CT), and high resolutions (up to 2.5 μm) were applied to the pore-scale LBM simulations. For the sake of numerical stability, the digital images were "cleaned" by closing the dead holes and removing the suspended particles in sandstone rocks. In addition, the effect of chemical reactions occurred in the carbonation process on the permeability was taken into account. For the wetting brine and non-wetting supercritical CO2 flows, they were treated as the immiscible fluids and were driven by pressure gradients in sandstone rocks. Relative permeabilities of brine and supercritical CO2 in sandstone rocks were estimated. Particularly the dynamic saturation was applied to improve the reliability of the calculations of the relative permeabilities. Moreover, the effects of the viscosity ratio of the two immiscible fluids and the resolution of digital images on the relative permeability were systematically investigated.

  5. Effect of Flow Direction on Relative Permeability Curves in Water/Gas Reservoir System: Implications in Geological CO2 Sequestration

    Directory of Open Access Journals (Sweden)

    Abdulrauf Rasheed Adebayo

    2017-01-01

    Full Text Available The effect of gravity on vertical flow and fluids saturation, especially when flow is against gravity, is not often a subject of interest to researchers. This is because of the notion that flow in subsurface formations is usually in horizontal direction and that vertical flow is impossible or marginal because of the impermeable shales or silts overlying them. The density difference between two fluids (usually oil and water flowing in the porous media is also normally negligible; hence gravity influence is neglected. Capillarity is also often avoided in relative permeability measurements in order to satisfy some flow equations. These notions have guided most laboratory core flooding experiments to be conducted in horizontal flow orientation, and the data obtained are as good as what the experiments tend to mimic. However, gravity effect plays a major role in gas liquid systems such as CO2 sequestration and some types of enhanced oil recovery techniques, particularly those involving gases, where large density difference exists between the fluid pair. In such cases, laboratory experiments conducted to derive relative permeability curves should take into consideration gravity effects and capillarity. Previous studies attribute directional dependence of relative permeability and residual saturations to rock anisotropy. It is shown in this study that rock permeability, residual saturation, and relative permeability depend on the interplay between gravity, capillarity, and viscous forces and also the direction of fluid flow even when the rock is isotropic. Rock samples representing different lithology and wide range of permeabilities were investigated through unsteady-state experiments covering drainage and imbibition in both vertical and horizontal flow directions. The experiments were performed at very low flow rates to capture capillarity. The results obtained showed that, for each homogeneous rock and for the same flow path along the core length

  6. Hydrothermal alteration and permeability changes in granitic intrusions related to Sn-W deposits : case study of Panasqueira (Portugal)

    Science.gov (United States)

    Launay, Gaetan; Sizaret, Stanislas; Guillou-Frottier, Laurent; Gloaguen, Eric; Melleton, Jérémie; Pichavant, Michel; Champallier, Rémi; Pinto, Filipe

    2017-04-01

    The Panasqueira Sn-W deposit occurs as a dense network of flat wolframite and cassiterite-bearing quartz veins concentrated in the vicinity of a hidden greisen cupola, and to a lesser extent as disseminated cassiterites in the greisen. Previous studies (Thadeu 1951; 1979) have suggested that the Panasqueira deposit is genetically related to magmatic activity for which the most part is unexposed, and being only represented by the greisen cupola. Hydrothermal fluid circulation during the final stages of granite crystallisation has probably led to the greisenisation of the cupola followed by the deposition of the mineralization in the veins system. Mineral replacement reactions that occurred during the greisenisation could affect rock properties (porosity, density and permeability) which control fluid circulation in the granite. This study aims to investigate effects of greisenisation reactions on the dynamic (time varying) permeability that ultimately leads to fluid circulation in the greisen cupola. To do so, petrological study and experimental determinations of hydrodynamic features (porosity and permeability) for different granite alteration levels and petrographic types (unaltered granite to greisen) are combined and then integrated in coupled numerical models of fluid circulation around the granitic intrusion. Greisen occurs in the apical part of the granitic body and results in the pervasive alteration of the granite along the granite-schist contact. This greisen consists mainly of quartz and muscovite formed by the replacement of feldspars and bleaching of biotites of the initial granite. Otherwise, greisen is generally vuggy which suggests a porosity increase of the granite during hydrothermal alteration processes. This porosity increase has a positive effect on the permeability of the granitic system. Indeed, experimental measurements of permeability with the Paterson press indicate that the initial granite is impermeable (10-20 m2) whereas the greisen is

  7. Persistent Functional Languages: Toward Functional Relational Databases

    NARCIS (Netherlands)

    Wevers, L.

    2014-01-01

    Functional languages provide new approaches to concurrency control, based on techniques such as lazy evaluation and memoization. We have designed and implemented a persistent functional language based on these ideas, which we plan to use for the implementation of a relational database system. With

  8. Permeability measurement of some barrier materials as a function of temperature and pressure

    International Nuclear Information System (INIS)

    Maqsood, M.; Faisal, S.; Ali, J.; Usman, A.; Alamgir, K.; Farooq, K.

    2011-01-01

    Barrier materials possess the ability to restrict the passage of gases, vapors, and organic liquids through their boundaries. These barrier materials have large number of applications in industry and scientific research. To measure the permeability of barrier materials, a specific gas flow system has been developed, pure helium gas is used to measure the back ground reading through SS-316. The permeability and break-through time has been measured through Inconel X-750, NBR and Viton below and above the atmospheric pressure and at different temperatures 20 deg. C, 40 deg. C and 70 deg. C. (author)

  9. Relative Impacts of Low Permeability Subsurface Deposits on Recharge Basin Infiltration Rates

    Science.gov (United States)

    Oconnell, P.; Becker, M.; Pham, C.; Rodriguez, G.; Hutchinson, A.; Plumlee, M.

    2017-12-01

    Artificial recharge of aquifers through spreading basins has become an important component of water management in semi-arid climates. The rate at which water can be recharged in these basins is limited by the natural vertical permeability of the underlying deposits which may be highly variable both laterally and vertically. To help understand hydrostratigraphic controls on recharge, a newly constructed basin was surveyed and instrumented. Prior to flooding the basin, lithology was characterized by shallow hand coring, direct push coring, ground penetrating radar, and electrical resistivity. After flooding, recharge was monitored through piezometers, electrical resistivity, and a network of fiber optic distributed temperature sensing (DTS). The DTS network used temperature as a tracer to measure infiltration rate on 25 cm intervals both laterally and vertically. Several hundred paired DTS time series datasets (from fiber optic cables located at 0 and 0.5 meters below ground surface) were processed with the cross-wavelet transform (XWT) to calculate spatially and temporally continuous infiltration rates, which can be interpolated and animated to visualize heterogeneity. Time series data from 8-meter deep, vertically oriented DTS cables reveal depth intervals where infiltration rates vary. Inverted resistivity sections from repeated dipole-dipole surveys along the sidewall of a spreading basin exhibit a positive correlation with the distribution of relatively high and low infiltration rates, indicating zones of preferential downward (efficient) and lateral (inefficient) flow, respectively. In contrast to other monitored basins, no perching was observed in the vertically oriented DTS cables. The variation in recharge across the basin and the appearance of subsurface lateral flow can be explained in context of the alluvial depositional environment.

  10. Evaluating the Influence of Pore Architecture and Initial Saturation on Wettability and Relative Permeability in Heterogeneous, Shallow-Shelf Carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Byrnes, Alan P.; Bhattacharya, Saibal; Victorine, John; Stalder, Ken

    2007-09-30

    Thin (3-40 ft thick), heterogeneous, limestone and dolomite reservoirs, deposited in shallow-shelf environments, represent a significant fraction of the reservoirs in the U.S. midcontinent and worldwide. In Kansas, reservoirs of the Arbuckle, Mississippian, and Lansing-Kansas City formations account for over 73% of the 6.3 BBO cumulative oil produced over the last century. For these reservoirs basic petrophysical properties (e.g., porosity, absolute permeability, capillary pressure, residual oil saturation to waterflood, resistivity, and relative permeability) vary significantly horizontally, vertically, and with scale of measurement. Many of these reservoirs produce from structures of less than 30-60 ft, and being located in the capillary pressure transition zone, exhibit vertically variable initial saturations and relative permeability properties. Rather than being simpler to model because of their small size, these reservoirs challenge characterization and simulation methodology and illustrate issues that are less apparent in larger reservoirs where transition zone effects are minor and most of the reservoir is at saturations near S{sub wirr}. These issues are further augmented by the presence of variable moldic porosity and possible intermediate to mixed wettability and the influence of these on capillary pressure and relative permeability. Understanding how capillary-pressure properties change with rock lithology and, in turn, within transition zones, and how relative permeability and residual oil saturation to waterflood change through the transition zone is critical to successful reservoir management and as advanced waterflood and improved and enhanced recovery methods are planned and implemented. Major aspects of the proposed study involve a series of tasks to measure data to reveal the nature of how wettability and drainage and imbibition oil-water relative permeability change with pore architecture and initial water saturation. Focus is placed on

  11. Hydrologic and Pollutant Removal Performance of a Full-Scale, Fully Functional Permeable Pavement Parking Lot

    Science.gov (United States)

    In accordance with the need for full-scale, replicated studies of permeable pavement systems used in their intended application (parking lot, roadway, etc.) across a range of climatic events, daily usage conditions, and maintenance regimes to evaluate these systems, the EPA’s Urb...

  12. Literature review and recommendation of methods for measuring relative permeability of anhydrite from the Salado Formation at the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, R.L. [Colorado School of Mines, Golden, CO (United States). Dept. of Petroleum Engineering; Howarth, S.M. [Sandia National Labs., Albuquerque, NM (United States)

    1995-08-01

    This report documents a literature review of methods for measuring relative permeability as applied to low permeability anhydrite rock samples from the Salado Formation. About one hundred papers were reviewed, and four methods were identified as promising techniques for measuring the relative permeability of the Salado anhydrite: (1) the unsteady-state high-rate method, (2) the unsteady-state stationary-liquid method, (3) the unsteady-state centrifuge method, and (4) the unsteady-state low-rate method. Except for the centrifuge method, all have been used for low permeability rocks. The unsteady-state high-rate method is preferred for measuring relative permeability of Salado anhydrite, and the unsteady-state stationary-liquid method could be well suited for measuring gas relative permeability of Salado anhydrite. The unsteady-state low-rate method, which combines capillary pressure effects with relative permeability concepts may also prove effective. Likewise, the unsteady-state centrifuge method may be an efficient means for measuring brine relative permeability for Salado anhydrite, especially at high gas saturations.

  13. Literature review and recommendation of methods for measuring relative permeability of anhydrite from the Salado Formation at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Christiansen, R.L.

    1995-08-01

    This report documents a literature review of methods for measuring relative permeability as applied to low permeability anhydrite rock samples from the Salado Formation. About one hundred papers were reviewed, and four methods were identified as promising techniques for measuring the relative permeability of the Salado anhydrite: (1) the unsteady-state high-rate method, (2) the unsteady-state stationary-liquid method, (3) the unsteady-state centrifuge method, and (4) the unsteady-state low-rate method. Except for the centrifuge method, all have been used for low permeability rocks. The unsteady-state high-rate method is preferred for measuring relative permeability of Salado anhydrite, and the unsteady-state stationary-liquid method could be well suited for measuring gas relative permeability of Salado anhydrite. The unsteady-state low-rate method, which combines capillary pressure effects with relative permeability concepts may also prove effective. Likewise, the unsteady-state centrifuge method may be an efficient means for measuring brine relative permeability for Salado anhydrite, especially at high gas saturations

  14. Highly permeable polymeric membranes based on the incorporation of the functional water channel protein Aquaporin Z

    Science.gov (United States)

    Kumar, Manish; Grzelakowski, Mariusz; Zilles, Julie; Clark, Mark; Meier, Wolfgang

    2007-01-01

    The permeability and solute transport characteristics of amphiphilic triblock-polymer vesicles containing the bacterial water-channel protein Aquaporin Z (AqpZ) were investigated. The vesicles were made of a block copolymer with symmetric poly-(2-methyloxazoline)-poly-(dimethylsiloxane)-poly-(2-methyloxazoline) (PMOXA15-PDMS110-PMOXA15) repeat units. Light-scattering measurements on pure polymer vesicles subject to an outwardly directed salt gradient in a stopped-flow apparatus indicated that the polymer vesicles were highly impermeable. However, a large enhancement in water productivity (permeability per unit driving force) of up to ≈800 times that of pure polymer was observed when AqpZ was incorporated. The activation energy (Ea) of water transport for the protein-polymer vesicles (3.4 kcal/mol) corresponded to that reported for water-channel-mediated water transport in lipid membranes. The solute reflection coefficients of glucose, glycerol, salt, and urea were also calculated, and indicated that these solutes are completely rejected. The productivity of AqpZ-incorporated polymer membranes was at least an order of magnitude larger than values for existing salt-rejecting polymeric membranes. The approach followed here may lead to more productive and sustainable water treatment membranes, whereas the variable levels of permeability obtained with different concentrations of AqpZ may provide a key property for drug delivery applications. PMID:18077364

  15. Functional statistics and related fields

    CERN Document Server

    Bongiorno, Enea; Cao, Ricardo; Vieu, Philippe

    2017-01-01

    This volume collects latest methodological and applied contributions on functional, high-dimensional and other complex data, related statistical models and tools as well as on operator-based statistics. It contains selected and refereed contributions presented at the Fourth International Workshop on Functional and Operatorial Statistics (IWFOS 2017) held in A Coruña, Spain, from 15 to 17 June 2017. The series of IWFOS workshops was initiated by the Working Group on Functional and Operatorial Statistics at the University of Toulouse in 2008. Since then, many of the major advances in functional statistics and related fields have been periodically presented and discussed at the IWFOS workshops. .

  16. Perovskite-related oxide materials for oxygen-permeable electrochemical membrans

    OpenAIRE

    Naumovich, E. N.; Yaremchenko, A. A.; Viskup, A. P.; Kharton, V. V.

    2003-01-01

    This brief review is focused on the studies of mixed ionic-electronic conductors on the basis of lanthanum gallate doped with transition metal cations in the В sublattice. The substitution of gallium with iron, cobalt or nickel results in greater electronic conductivity, simultaneously keeping high level of the oxy-gen ionic transport. In particular, La0 90Sr0 10Ga0 65Ni0 20Mg0 1503d perovskite exhib-its attractive oxygen permeability, which is quite similar to that of La2Ni04- and (...

  17. Improving enzymatic activities and thermostability of a tri-functional enzyme with SOD, catalase and cell-permeable activities.

    Science.gov (United States)

    Luangwattananun, Piriya; Eiamphungporn, Warawan; Songtawee, Napat; Bülow, Leif; Isarankura Na Ayudhya, Chartchalerm; Prachayasittikul, Virapong; Yainoy, Sakda

    2017-04-10

    Synergistic action of major antioxidant enzymes, e.g., superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) is known to be more effective than the action of any single enzyme. Recently, we have engineered a tri-functional enzyme, 6His-MnSOD-TAT/CAT-MnSOD (M-TAT/CM), with SOD, CAT and cell-permeable activities. The protein actively internalized into the cells and showed superior protection against oxidative stress-induced cell death over native enzymes fused with TAT. To improve its molecular size, enzymatic activity and stability, in this study, MnSOD portions of the engineered protein were replaced by CuZnSOD, which is the smallest and the most heat resistant SOD isoform. The newly engineered protein, CAT-CuZnSOD/6His-CuZnSOD-TAT (CS/S-TAT), had a 42% reduction in molecular size and an increase in SOD and CAT activities by 22% and 99%, respectively. After incubation at 70°C for 10min, the CS/S-TAT retained residual SOD activity up to 54% while SOD activity of the M-TAT/CM was completely abolished. Moreover, the protein exhibited a 5-fold improvement in half-life at 70°C. Thus, this work provides insights into the design and synthesis of a smaller but much more stable multifunctional antioxidant enzyme with ability to enter mammalian cells for further application as protective/therapeutic agent against oxidative stress-related conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Finding related functional neuroimaging volumes

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    2004-01-01

    We describe a content-based image retrieval technique for finding related functional neuroimaging experiments by voxelization of sets of stereotactic coordinates in Talairach space, comparing the volumes and reporting related volumes in a sorted list. Voxelization is accomplished by convolving ea...

  19. Crustal permeability

    Science.gov (United States)

    Gleeson, Tom; Ingebritsen, Steven E.

    2016-01-01

    Permeability is the primary control on fluid flow in the Earth’s crust and is key to a surprisingly wide range of geological processes, because it controls the advection of heat and solutes and the generation of anomalous pore pressures.  The practical importance of permeability – and the potential for large, dynamic changes in permeability – is highlighted by ongoing issues associated with hydraulic fracturing for hydrocarbon production (“fracking”), enhanced geothermal systems, and geologic carbon sequestration.  Although there are thousands of research papers on crustal permeability, this is the first book-length treatment.  This book bridges the historical dichotomy between the hydrogeologic perspective of permeability as a static material property and the perspective of other Earth scientists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. 

  20. Problems of increasing of thermostability of highly permeable Ni-Zn ferrites and relative materials for telecommunications

    Energy Technology Data Exchange (ETDEWEB)

    Gonchar, A. E-mail: letyuk@mail.ru; Andreev, V.; Letyuk, L.; Shishkanov, A.; Maiorov, V

    2003-01-01

    The work considers ways of increasing of thermostability of ferrites of the basic systems NiO-ZnO-Fe{sub 2}O{sub 3} and MgO-ZnO-Fe{sub 2}O{sub 3} and relative materials for telecommunication. Sufficient results in increasing of the thermostability were achieved by doping Cu ions and controlling rejection of Fe{sub 2}O{sub 3} content from equimolar composition. These results allow to increase the Curie temperature to 130-140 deg. C for Ni-Zn ferrites with initial permeability 2000.

  1. Notional Permeability

    NARCIS (Netherlands)

    Kik, R.; Van den Bos, J.P.; Maertens, J.; Verhagen, H.J.; Van der Meer, J.W.

    2012-01-01

    Different layer design of a rock slope and under layers has a large effect on the strengths on the rock slope itself. In the stability formula developed of VAN DER MEER [1988] this effect is represented by the term Notional Permeability with symbol P. A more open, or permeable, structure underneath

  2. Relative rates of albumin equilibration in the skin interstitium and lymph during increased permeability

    International Nuclear Information System (INIS)

    Powers, M.R.; Wallace, J.R.; Bell, D.R.

    1986-01-01

    The initial equilibration of 125 I-labelled albumin between the vascular and extravascular compartments was studied in hindpaw heel skin of anesthetized rabbits. Bradykinin (0.3 μg/min) was infused into a small branch of the femoral artery. A second group of rabbits served as control. Following bradykinin, prenodal popliteal lymph flow was 4 times control flow. The lymph-to-plasma concentration ratios for total protein and albumin were, respectively, 60% and 50% larger than control. Tissue albumin concentration was twice control. After reaching a steady, elevated lymph flow, tracer albumin was infused to maintain plasma activity constant for 3 hrs. The plasma volume in tissue samples was measured using 131 I-labeled albumin injected 10 min before ending the experiment. Endogenous albumin was measured in plasma, lymph, and tissue samples using rocket electroimmunoassay. After 3 hrs of tracer infusion, lymph specific activity was 3 times greater than control. In the control group, plasma albumin equilibrated more rapidly with lymph than with tissue (p < 0.05). Following bradykinin, extravascular specific activity was 4 times control, resulting in lymph and tissue equilibrating with plasma at similar rates. Thus, increasing capillary permeability causes the extravascular albumin mass to behave as if distributed in a single compartment

  3. Diabetic and sympathetic influences on the water permeability barrier function of human skin as measured using transepidermal water loss: A case-control study.

    Science.gov (United States)

    Han, Seung Hoon; Park, Ji Woong

    2017-11-01

    The presence of long-standing hyperglycemic conditions has been suggested to lead to many skin problems associated with an impaired skin barrier function. However, the relationship between impaired skin barrier status and altered peripheral nervous system function has not yet been determined. The purpose of this study was to investigate the water evaporation rate as a measure of the permeability barrier function of diabetic skin and its relationship to diabetic sensorimotor polyneuropathy (DSPN) and peripheral autonomic neuropathy (PAN) using well-controlled confounding variables.This case-control study included 42 participants with chronic diabetes and 43 matched healthy controls. The diabetic group underwent a nerve conduction study and sympathetic skin response (SSR) test to confirm the presence of DSPN and PAN, respectively. Different skin regions were analyzed using the noninvasive Tewameter instrument (Courage + Khazaka Electronic GmbH, Cologne, Germany). The impacts of PAN, DSPN, age, and diabetes duration on the values of transepidermal water loss (TEWL) were each analyzed and compared between the groups.Regardless of the presence of DSPN or PAN, the TEWL values as measured on the distal extremities were significantly lower in the diabetic group than in the control group. In the diabetic group, participants with abnormal SSR test results showed decreased TEWL values in the finger, sole, and first toe, as compared with participants with normal SSR test results. In the control group, age showed a negative correlation with the TEWL values with respect to some measured regions. However, in the diabetic group, there was no significant correlation between either patient age or diabetes duration and TEWL values.The presence of a long-term hyperglycemic state can reduce the permeability barrier function of the skin, a phenomenon that might be related to the presence of an impaired peripheral sympathetic nervous system, rather than peripheral sensorimotor

  4. Early-life seizures alter synaptic calcium-permeable AMPA receptor function and plasticity

    Science.gov (United States)

    Lippman-Bell, Jocelyn J.; Zhou, Chengwen; Sun, Hongyu; Feske, Joel S.; Jensen, Frances E.

    2016-01-01

    Calcium (Ca2+)-mediated1 signaling pathways are critical to synaptic plasticity. In adults, the NMDA glutamate receptor (NMDAR) represents a major route for activity-dependent synaptic Ca2+ entry. However, during neonatal development, when synaptic plasticity is high, many AMPA glutamate receptors (AMPARs) are also permeable to Ca2+ (CP-AMPAR) due to low GluA2 subunit expression, providing an additional route for activity- and glutamate-dependent Ca2+ influx and subsequent signaling. Therefore, altered hippocampal Ca2+ signaling may represent an age-specific pathogenic mechanism. We thus aimed to assess Ca2+ responses 48 hours after hypoxia-induced neonatal seizures (HS) in postnatal day (P)10 rats, a post-seizure time point at which we previously reported LTP attenuation. We found that Ca2+ responses were higher in brain slices from post-HS rats than in controls and this increase was CP-AMPAR-dependent. To determine whether synaptic CP-AMPAR expression was also altered post-HS, we assessed the expression of GluA2 at hippocampal synapses and the expression of long-term depression (LTD), which has been linked to the presence of synaptic GluA2. Here we report a decrease 48 hours after HS in synaptic GluA2 expression at synapses and LTD in hippocampal CA1. Given the potentially critical role of AMPAR trafficking in disease progression, we aimed to establish whether post-seizure in vivo AMPAR antagonist treatment prevented the enhanced Ca2+ responses, changes in GluA2 synaptic expression, and diminished LTD. We found that NBQX treatment prevents all three of these post-seizure consequences, further supporting a critical role for AMPARs as an age-specific therapeutic target. PMID:27521497

  5. Isthmin is a novel vascular permeability inducer that functions through cell-surface GRP78-mediated Src activation.

    Science.gov (United States)

    Venugopal, Shruthi; Chen, Mo; Liao, Wupeng; Er, Shi Yin; Wong, Wai-Shiu Fred; Ge, Ruowen

    2015-07-01

    Isthmin (ISM) is a recently identified 60 kDa secreted angiogenesis inhibitor. Two cell-surface receptors for ISM have been defined, the high-affinity glucose-regulated protein 78 kDa (GRP78) and the low-affinity αvβ5 integrin. As αvβ5 integrin plays an important role in pulmonary vascular permeability (VP) and ISM is highly expressed in mouse lung, we sought to clarify the role of ISM in VP. Recombinant ISM (rISM) dose-dependently enhances endothelial monolayer permeability in vitro and local dermal VP when administered intradermally in mice. Systemic rISM administration through intravenous injection leads to profound lung vascular hyperpermeability but not in other organs. Mechanistic investigations using molecular, biochemical approaches and specific chemical inhibitors revealed that ISM-GRP78 interaction triggers a direct interaction between GRP78 and Src, leading to Src activation and subsequent phosphorylation of adherens junction proteins and loss of junctional proteins from inter-endothelial junctions, resulting in enhanced VP. Dynamic studies of Src activation, VP and apoptosis revealed that ISM induces VP directly via Src activation while apoptosis contributes indirectly only after prolonged treatment. Furthermore, ISM is significantly up-regulated in lipopolysaccharide (LPS)-treated mouse lung. Blocking cell-surface GRP78 by systemic infusion of anti-GRP78 antibody significantly attenuates pulmonary vascular hyperpermeability in LPS-induced acute lung injury (ALI) in mice. ISM is a novel VP inducer that functions through cell-surface GRP78-mediated Src activation as well as induction of apoptosis. It induces a direct GRP78-Src interaction, leading to cytoplasmic Src activation. ISM contributes to pulmonary vascular hyperpermeability of LPS-induced ALI in mice. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  6. Pore Structure and Diagenetic Controls on Relative Permeability: Implications for Enhanced Oil Recovery and CO2 Storage

    Science.gov (United States)

    Feldman, J.; Dewers, T. A.; Heath, J. E.; Cather, M.; Mozley, P.

    2016-12-01

    Multiphase flow in clay-bearing sandstones of the Morrow Sandstone governs the efficiency of CO2 storage and enhanced oil recovery at the Farnsworth Unit, Texas. This formation is the target for enhanced oil recovery and injection of one million metric ton of anthropogenically-sourced CO2. The sandstone hosts eight major flow units that exhibit distinct microstructural characteristics due to diagenesis, including: "clean" macro-porosity; quartz overgrowths constricting some pores; ghost grains; intergranular porosity filled by microporous authigenic clay; and feldspar dissolution. We examine the microstructural controls on macroscale (core scale) relative permeability and capillary pressure behavior through: X-ray computed tomography, Robomet.3d, and focused ion beam-scanning electron microscopy imaging of the pore structure of the major flow units of the Morrow Sandstone; relative permeability and capillary pressure in the laboratory using CO2, brine, and oil at reservoir pressure and effective stress conditions. The combined data sets inform links between patterns of diagenesis and multiphase flow. These data support multiphase reservoir simulation and performance assessment by the Southwest Regional Partnership on Carbon Sequestration (SWP). Funding for this project is provided by the U.S. Department of Energy's National Energy Technology Laboratory through the SWP under Award No. DE-FC26-05NT42591. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. Unexpected effects of peripherally administered kynurenic acid on cortical spreading depression and related blood–brain barrier permeability

    Directory of Open Access Journals (Sweden)

    Oláh G

    2013-09-01

    Full Text Available Gáspár Oláh,1 Judit Herédi,1 Ákos Menyhárt,1 Zsolt Czinege,2 Dávid Nagy,1 János Fuzik,1 Kitti Kocsis,1 Levente Knapp,1 Erika Krucsó,1 Levente Gellért,1 Zsolt Kis,1 Tamás Farkas,1 Ferenc Fülöp,3 Árpád Párdutz,4 János Tajti,4 László Vécsei,4 József Toldi1 1Department of Physiology, Anatomy and Neuroscience, 2Department of Software Engineering, 3Institute of Pharmaceutical Chemistry and MTA-SZTE Research Group for Stereochemistry, 4Department of Neurology and MTA-SZTE Neuroscience Research Group, University of Szeged, Szeged, Hungary Abstract: Cortical spreading depression (CSD involves a slowly-propagating depolarization wave in the cortex, which can appear in numerous pathophysiological conditions, such as migraine with aura, stroke, and traumatic brain injury. Neurons and glial cells are also depolarized transiently during the phenomena. CSD is followed by a massive increase in glutamate release and by changes in the brain microcirculation. The aim of this study was to investigate the effects of two N-methyl-D-aspartate receptor antagonists, endogenous kynurenic acid (KYNA and dizocilpine, on CSD and the related blood–brain barrier (BBB permeability in rats. In intact animals, KYNA hardly crosses the BBB but has some positive features as compared with its precursor L-Kynurenine, which is frequently used in animal studies (KYNA cannot be metabolized to excitotoxic agents such as 3-hydroxy-L-kynurenine and quinolinic acid. We therefore investigated the possible effects of peripherally administered KYNA. Repetitive CSD waves were elicited by the application of 1 M KCl solution to the cortex. Direct current-electrocorticograms were measured for 1 hour. Four parameters of the waves were compared. Evans blue dye and fluorescent microscopy were used to study the possible changes in the permeability of the BBB. The results demonstrated that N-methyl-D-aspartate receptor antagonists can reduce the number of CSD waves and decrease

  8. Effects of ambient air particulate exposure on blood-gas barrier permeability and lung function

    DEFF Research Database (Denmark)

    Bräuner, Elvira Vaclavik; Mortensen, Jann; Møller, Peter

    2009-01-01

    function and Clara cell 16 (CC16) protein release in healthy young subjects. Twenty-nine nonsmokers participated in a randomized, two-factor crossover study with or without biking exercise for 180 min and with 24-h exposure to particle-rich (6169-15,362 particles/cm(3); 7.0-11.6 microg/m(3) PM(2.5); 7...

  9. Transformable ferroelectric control of dynamic magnetic permeability

    Science.gov (United States)

    Jiang, Changjun; Jia, Chenglong; Wang, Fenglong; Zhou, Cai; Xue, Desheng

    2018-02-01

    Magnetic permeability, which measures the response of a material to an applied magnetic field, is crucial to the performance of magnetic devices and related technologies. Its dynamic value is usually a complex number with real and imaginary parts that describe, respectively, how much magnetic power can be stored and lost in the material. Control of permeability is therefore closely related to energy redistribution within a magnetic system or energy exchange between magnetic and other degrees of freedom via certain spin-dependent interactions. To avoid a high power consumption, direct manipulation of the permeability with an electric field through magnetoelectric coupling leads to high efficiency and simple operation, but remains a big challenge in both the fundamental physics and material science. Here we report unambiguous evidence of ferroelectric control of dynamic magnetic permeability in a Co /Pb (Mg1/3Nb2/3) 0.7Ti0.3O3 (Co/PMN-PT) heterostructure, in which the ferroelectric PMN-PT acts as an energy source for the ferromagnetic Co film via an interfacial linear magnetoelectric interaction. The electric field tuning of the magnitude and line shape of the permeability offers a highly localized means of controlling magnetization with ultralow power consumption. Additionally, the emergence of negative permeability promises a new way of realizing functional nanoscale metamaterials with adjustable refraction index.

  10. Topical antihistamines display potent anti-inflammatory activity linked in part to enhanced permeability barrier function

    DEFF Research Database (Denmark)

    Lin, Tzu-Kai; Man, Mao-Qiang; Santiago, Juan-Luis

    2013-01-01

    antagonists likely oppose mast cell-derived histamines. In four immunologically diverse, murine disease models, characterized by either inflammation alone (acute irritant contact dermatitis, acute allergic contact dermatitis) or by prominent barrier abnormalities (subacute allergic contact dermatitis, atopic...... of epidermal differentiation, leading to thickened cornified envelopes; and (ii) enhanced epidermal lipid synthesis and secretion. As barrier homeostasis was enhanced to a comparable extent in mast cell-deficient mice, with no further improvement following application of topical H1/2r antagonists, H1/2r...... dermatitis), topical H1/2r agonists aggravated, whereas H1/2r antagonists improved, inflammation and/or barrier function. The apparent ability of topical H1r/2r antagonists to target epidermal H1/2r could translate into increased efficacy in the treatment of inflammatory dermatoses, likely due to decreased...

  11. Soil Water Retention and Relative Permeability for Conditions from Oven-Dry to Full Saturation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.

    2011-11-04

    Common conceptual models for unsaturated flow often rely on the oversimplified representation of medium pores as a bundle of cylindrical capillaries and assume that the matric potential is attributed to the capillary force only. The adsorptive surface forces are ignored. It is often assumed that aqueous flow is negligible when a soil is near or at the residual water content. These models are successful at high and medium water contents but often give poor results at low water contents. These models do not apply to conditions at which the water content is less than the residual water content. We extend the lower bound of existing water-retention functions and conductivity models from residual water content to the oven-dry condition (i.e., zero water content) by defining a state-dependent, residual-water content for a soil drier than a critical value. Furthermore, a hydraulic conductivity model for smooth uniform spheres was modified by introducing a correction factor to describe the film flow-induced hydraulic conductivity for natural porous media. The total unsaturated hydraulic conductivity is the sum of those due to capillary and film flow. The extended retention and conductivity models were verified measurements. Results show that, when the soil is at high and intermediate water content, there is no difference between the un-extended and the extended models; when the soil is at low water content, the un-extended models overestimate the water content but underestimate the conductivity. The extended models match the retention and conductivity measurements well.

  12. Soil Water Retention and Relative Permeability for Full Range of Saturation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.

    2010-09-28

    Common conceptual models for unsaturated flow often rely on the oversimplified representation of medium pores as a bundle of cylindrical capillaries and assume that the matric potential is attributed to capillary forces only. The adsorptive surface forces are ignored. It is often assumed that aqueous flow is negligible when a soil is near or at the residual water content. These models are successful at high and medium water contents but often give poor results at low water contents. These models do not apply to conditions at which water content is less than the residual water content. We extend the lower bound of existing water-retention functions and conductivity models from residual water content to the oven-dry condition (i.e., zero water content) by defining a state-dependent, residual-water content for a soil drier than a critical value. Furthermore, a hydraulic conductivity model for smooth uniform spheres was modified by introducing a correction factor to describe the film flow-induced hydraulic conductivity for natural porous media. The total unsaturated hydraulic conductivity is the sum of those due to capillary and film flow. The extended retention and conductivity models were verified with six datasets from the literature. Results show that, when the soil is at high and intermediate water content, there is no difference between the un-extended and the extended models; when the soil is at low water content, the un-extended models overestimate the water content but under-estimate the conductivity while the extended models match the retention and conductivity measurements well.

  13. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    Directory of Open Access Journals (Sweden)

    J. Moeys

    2012-07-01

    Full Text Available Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedotransfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved.

    Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42. Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = −0.26 due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72. Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is

  14. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    Science.gov (United States)

    Moeys, J.; Larsbo, M.; Bergström, L.; Brown, C. D.; Coquet, Y.; Jarvis, N. J.

    2012-07-01

    Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved. Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42). Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = -0.26) due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72). Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the

  15. Stem sapwood permeability in relation to crown dominance and site quality in self-thinning fire-origin lodgepole pine stands.

    Science.gov (United States)

    Reid, Douglas E B; Silins, Uldis; Lieffers, Victor J

    2003-08-01

    Stem sapwood hydraulic permeability, tree leaf area, sapwood basal area, earlywood to latewood ratio of annual rings, radial variation in hydraulic permeability and stem hydraulic capacity were examined in dominant (D), codominant (CD) and suppressed (SP) lodgepole pine (Pinus contorta Dougl. ex Loud.) trees growing on medium and poor sites. Hydraulic permeability on a sapwood area basis (ks) was lower in suppressed trees (0.71 x 10(-12) m2) compared to dominants (1.97 x 10(-12) m2) and codominants (1.79 x 10(-12) m2), and higher on medium than on poor sites. The leaf/sapwood area ratio (S) varied with crown dominance position (D > CD > SP) but not by site type. Leaf specific conductivity (kL) did not vary between crown classes or site types. The relationship between leaf area and stem hydraulic supply capacity (Q*) was strong, but differed among crown classes. Dominant trees and trees from the medium sites had a greater proportion of earlywood in outer rings of sapwood than suppressed trees. Sapwood permeability declined from the cambium to the sapwood-heartwood boundary in all samples, but the decline was more gradual in dominant trees compared to codominant and suppressed trees; differences in the radial variation in sapwood permeability may be related to differences in S. Sapwood permeability is positively related to crown dominance, whereas subdominant (CD and SP) trees have greater Q* in relation to leaf area, leading us to propose that this may give subdominant trees a survival advantage, slowing self-thinning.

  16. Cisplatin impairs rat liver mitochondrial functions by inducing changes on membrane ion permeability: Prevention by thiol group protecting agents

    International Nuclear Information System (INIS)

    Custodio, Jose B.A.; Cardoso, Carla M.P.; Santos, Maria S.; Almeida, Leonor M.; Vicente, Joaquim A.F.; Fernandes, Maria A.S.

    2009-01-01

    Cisplatin (CisPt) is the most important platinum anticancer drug widely used in the treatment of head, neck, ovarian and testicular cancers. However, the mechanisms by which CisPt induces cytotoxicity, namely hepatotoxicity, are not completely understood. The goal of this study was to investigate the influence of CisPt on rat liver mitochondrial functions (Ca 2+ -induced mitochondrial permeability transition (MPT), mitochondrial bioenergetics, and mitochondrial oxidative stress) to better understand the mechanism underlying its hepatotoxicity. The effect of thiol group protecting agents and some antioxidants against CisPt-induced mitochondrial damage was also investigated. Treatment of rat liver mitochondria with CisPt (20 nmol/mg protein) induced Ca 2+ -dependent mitochondrial swelling, depolarization of membrane potential (ΔΨ), Ca 2+ release, and NAD(P)H fluorescence intensity decay. These effects were prevented by cyclosporine A (CyA), a potent and specific inhibitor of the MPT. In the concentration range of up to 40 nmol/mg protein, CisPt slightly inhibited state 3 and stimulated state 2 and state 4 respiration rates using succinate as respiratory substrate. The respiratory indexes, respiratory control ratio (RCR) and ADP/O ratios, the ΔΨ, and the ADP phosphorylation rate were also depressed. CisPt induced mitochondrial inner membrane permeabilization to protons (proton leak) but did not induce significant changes on mitochondrial H 2 O 2 generation. All the effects induced by CisPt on rat liver mitochondria were prevented by thiol group protecting agents namely, glutathione (GSH), dithiothreitol (DTT), N-acetyl-L-cysteine (NAC) and cysteine (CYS), whereas superoxide-dismutase (SOD), catalase (CAT) and ascorbate (ASC) were without effect. In conclusion, the anticancer drug CisPt: (1) increases the sensitivity of mitochondria to Ca 2+ -induced MPT; (2) interferes with mitochondrial bioenergetics by increasing mitochondrial inner membrane permeabilization to

  17. The relativity of biological function.

    Science.gov (United States)

    Laubichler, Manfred D; Stadler, Peter F; Prohaska, Sonja J; Nowick, Katja

    2015-12-01

    Function is a central concept in biological theories and explanations. Yet discussions about function are often based on a narrow understanding of biological systems and processes, such as idealized molecular systems or simple evolutionary, i.e., selective, dynamics. Conflicting conceptions of function continue to be used in the scientific literature to support certain claims, for instance about the fraction of "functional DNA" in the human genome. Here we argue that all biologically meaningful interpretations of function are necessarily context dependent. This implies that they derive their meaning as well as their range of applicability only within a specific theoretical and measurement context. We use this framework to shed light on the current debate about functional DNA and argue that without considering explicitly the theoretical and measurement contexts all attempts to integrate biological theories are prone to fail.

  18. Zonulin upregulation is associated with increased gut permeability in subjects with type 1 diabetes and their relatives.

    Science.gov (United States)

    Sapone, Anna; de Magistris, Laura; Pietzak, Michelle; Clemente, Maria G; Tripathi, Amit; Cucca, Francesco; Lampis, Rosanna; Kryszak, Deborah; Cartenì, Maria; Generoso, Maddalena; Iafusco, Dario; Prisco, Francesco; Laghi, Francesca; Riegler, Gabriele; Carratu, Romano; Counts, Debra; Fasano, Alessio

    2006-05-01

    Zonulin, a protein that modulates intestinal permeability, is upregulated in several autoimmune diseases and is involved in the pathogenesis of autoimmune diabetes in the BB/Wor animal model of the disease. To verify the association between serum zonulin levels and in vivo intestinal permeability in patients with type 1 diabetes, both parameters were investigated in different stages of the autoimmune process. Forty-two percent (141 of 339) of the patients had abnormal serum zonulin levels, as compared with age-matched control subjects. The increased zonulin levels correlated with increased intestinal permeability in vivo and changes in claudin-1, claudin-2, and myosin IXB genes expression, while no changes were detected in ZO1 and occludin genes expression. When tested in serum samples collected during the pre-type 1 diabetes phase, elevated serum zonulin was detected in 70% of subjects and preceded by 3.5 +/- 0.9 years the onset of the disease in those patients who went on to develop type 1 diabetes. Combined, these results suggest that zonulin upregulation is associated with increased intestinal permeability in a subgroup of type 1 diabetic patients. Zonulin upregulation seems to precede the onset of the disease, providing a possible link between increased intestinal permeability, environmental exposure to non-self antigens, and the development of autoimmunity in genetically susceptible individuals.

  19. ROS-mediated PARP activity undermines mitochondrial function after permeability transition pore opening during myocardial ischemia-reperfusion.

    Science.gov (United States)

    Schriewer, Jacqueline M; Peek, Clara Bien; Bass, Joseph; Schumacker, Paul T

    2013-04-18

    Ischemia-reperfusion (I/R) studies have implicated oxidant stress, the mitochondrial permeability transition pore (mPTP), and poly(ADP-ribose) polymerase (PARP) as contributing factors in myocardial cell death. However, the interdependence of these factors in the intact, blood-perfused heart is not known. We therefore wanted to determine whether oxidant stress, mPTP opening, and PARP activity contribute to the same death pathway after myocardial I/R. A murine left anterior descending coronary artery (LAD) occlusion (30 minutes) and release (1 to 4 hours) model was employed. Experimental groups included controls and antioxidant-treated, mPTP-inhibited, or PARP-inhibited hearts. Antioxidant treatment prevented oxidative damage, mPTP opening, ATP depletion, and PARP activity, placing oxidant stress as the proximal death trigger. Genetic deletion of cyclophilin D (CypD(-/-)) prevented loss of total NAD(+) and PARP activity, and mPTP-mediated loss of mitochondrial function. Control hearts showed progressive mitochondrial depolarization and loss of ATP from 1.5 to 4 hours of reperfusion, but not outer mitochondrial membrane rupture. Neither genetic deletion of PARP-1 nor its pharmacological inhibition prevented the initial mPTP-mediated depolarization or loss of ATP, but PARP ablation did allow mitochondrial recovery by 4 hours of reperfusion. These results indicate that oxidant stress, the mPTP, and PARP activity contribute to a single death pathway after I/R in the heart. PARP activation undermines cell survival by preventing mitochondrial recovery after mPTP opening early in reperfusion. This suggests that PARP-mediated prolongation of mitochondrial depolarization contributes significantly to cell death via an energetic crisis rather than by mitochondrial outer membrane rupture.

  20. Completely monotonic functions related to logarithmic derivatives of entire functions

    DEFF Research Database (Denmark)

    Pedersen, Henrik Laurberg

    2011-01-01

    The logarithmic derivative l(x) of an entire function of genus p and having only non-positive zeros is represented in terms of a Stieltjes function. As a consequence, (-1)p(xml(x))(m+p) is a completely monotonic function for all m ≥ 0. This generalizes earlier results on complete monotonicity...... of functions related to Euler's psi-function. Applications to Barnes' multiple gamma functions are given....

  1. Hydrologic and Pollutant Removal Performance of a Full-Scale, Fully Functional Permeable Pavement Parking Lot - paper

    Science.gov (United States)

    To meet the need for long-term, full-scale, replicated studies of permeable pavement systems used in their intended application (parking lot, roadway, etc.) across a range of climatic events, daily usage conditions, and maintenance regimes to evaluate these systems, the EPA’s Urb...

  2. Commutation relations for functions of operators

    International Nuclear Information System (INIS)

    Transtrum, Mark K.; Van Huele, Jean-Francois S.

    2005-01-01

    We derive an expression for the commutator of functions of operators with constant commutations relations in terms of the partial derivatives of these functions. This result extends the well-known commutation relation between one operator and a function of another operator. We discuss the range of applicability of the formula with examples in quantum mechanics

  3. An Integrated Capillary, Buoyancy, and Viscous-Driven Model for Brine/CO2Relative Permeability in a Compositional and Parallel Reservoir Simulator

    KAUST Repository

    Kong, X.; Delshad, M.; Wheeler, M. F.

    2012-01-01

    The effectiveness of CO2 storage in the saline aquifers is governed by the interplay of capillary, viscous, and buoyancy forces. Recent experimental study reveals the impact of pressure, temperature, and salinity on interfacial tension (IFT) between CO2 and brine. The dependence of CO2-brine relative permeability and capillary pressure on pressure (IFT) is also clearly evident in published experimental results. Improved understanding of the mechanisms that control the migration and trapping of CO2 in subsurface is crucial to design future storage projects that warrant long-term and safe containment. Simulation studies ignoring the buoyancy and also variation in interfacial tension and the effect on the petrophysical properties such as trapped CO2 saturations, relative permeability, and capillary pressure have a poor chance of making accurate predictions of CO2 injectivity and plume migration. We have developed and implemented a general relative permeability model that combines effects of pressure gradient, buoyancy, and IFT in an equation of state (EOS) compositional and parallel simulator. The significance of IFT variations on CO2 migration and trapping is assessed.

  4. An Integrated Capillary, Buoyancy, and Viscous-Driven Model for Brine/CO2Relative Permeability in a Compositional and Parallel Reservoir Simulator

    KAUST Repository

    Kong, X.

    2012-11-03

    The effectiveness of CO2 storage in the saline aquifers is governed by the interplay of capillary, viscous, and buoyancy forces. Recent experimental study reveals the impact of pressure, temperature, and salinity on interfacial tension (IFT) between CO2 and brine. The dependence of CO2-brine relative permeability and capillary pressure on pressure (IFT) is also clearly evident in published experimental results. Improved understanding of the mechanisms that control the migration and trapping of CO2 in subsurface is crucial to design future storage projects that warrant long-term and safe containment. Simulation studies ignoring the buoyancy and also variation in interfacial tension and the effect on the petrophysical properties such as trapped CO2 saturations, relative permeability, and capillary pressure have a poor chance of making accurate predictions of CO2 injectivity and plume migration. We have developed and implemented a general relative permeability model that combines effects of pressure gradient, buoyancy, and IFT in an equation of state (EOS) compositional and parallel simulator. The significance of IFT variations on CO2 migration and trapping is assessed.

  5. Effect of temperature and relative humidity on the water vapour permeability and mechanical properties of cassava starch and soy protein concentrate based edible films.

    Science.gov (United States)

    Chinma, C E; Ariahu, C C; Alakali, J S

    2015-04-01

    The effect of temperature and relative humidity on the water vapour permeability (WVP) and mechanical properties of cassava starch and soy protein concentrate (SPC) based edible films containing 20 % glycerol level were studied. Tensile strength and elastic modulus of edible films increased with increase in temperature and decreased with increase in relative humidity, while elongation at break decreased. Water vapour permeability of the films increased (2.6-4.3 g.mm/m(2).day.kPa) with increase in temperature and relative humidity. The temperature dependence of water vapour permeation of cassava starch-soy protein concentrate films followed Arrhenius relationship. Activation energy (Ea) of water vapour permeation of cassava starch-soy protein concentrate edible films ranged from 1.9 to 5.3 kJ/mol (R (2)  ≥ 0.93) and increased with increase in SPC addition. The Ea values were lower for the bio-films than for polyvinylidene chloride, polypropylene and polyethylene which are an indication of low water vapour permeability of the developed biofilms compared to those synthetic films.

  6. Tetraphenylphosphonium-selective electrode as a tool for evaluating mitochondrial permeability transition pore function in isolated rat hepatocytes

    Czech Academy of Sciences Publication Activity Database

    Lábajová, A.; Kofránek, J.; Křiváková, P.; Červinková, Z.; Drahota, Zdeněk

    2006-01-01

    Roč. 25, č. 3 (2006), s. 325-331 ISSN 0231-5882 R&D Projects: GA ČR(CZ) GD303/03/H065; GA ČR(CZ) GA303/06/1261 Institutional research plan: CEZ:AV0Z50110509 Keywords : hepatocytes * mitochondria * membrane-permeability-transition –pore Subject RIV: CE - Biochemistry Impact factor: 0.771, year: 2006

  7. Measurement of low permeabilities and of pinpoint hydraulic load variations as a function of depth in crystalline formations

    International Nuclear Information System (INIS)

    1987-01-01

    As part of the programme on management and storage of radioactive wastes, the PIEZOFOR system was improved in two directions, with a view to hydrogeological measurements in low permeability crystalline formations: - the special casing of the boreholes, on the one hand; - the measurement probe, on the other hand. In parallel, a specific software package for automatic interpretation of the measurements was put into operation [fr

  8. Evaluation of different toxicity assays applied to proliferating cells and to stratified epithelium in relation to permeability enhancement with glycocholate

    DEFF Research Database (Denmark)

    Eirheim, Heidi Ugelstad; Bundgaard, Christoffer; Nielsen, Hanne Mørck

    2004-01-01

    The purpose of the present study was to evaluate different toxicity assays for use on proliferating buccal TR146 cells and on stratified TR146 epithelium and to compare these results to the permeability enhancing effect of glycocholate (GC). Both the proliferating cells and the epithelium were...... across the epithelium concurrent with a decrease in the transepithelial electrical resistance (TEER) was also determined. The robustness of the epithelium was significantly higher than that of the proliferating cells (P...

  9. Relating transport modeling to nanofiltration membrane fabrication: Navigating the permeability-selectivity trade-off in desalination pretreatment

    OpenAIRE

    Labban, Omar; Lienhard, John H

    2018-01-01

    Faced with a pressing need for membranes with a higher permeability and selectivity, the field of membrane technology can benefit from a systematic framework for designing membranes with the necessary physical characteristics. In this work, we present an approach through which transport modeling is employed in fabricating specialized nanofiltration membranes, that experimentally demonstrate enhanced selectivity. Specifically, the Donnan-Steric Pore Model with dielectric exclusion (DSPM-DE) is...

  10. PHYSICAL AND CHEMICAL PROPERTIES IN RELATION WITH SOIL PERMEABILITY IN THE AREA OF VELIKA GORICA WELL FIELD

    Directory of Open Access Journals (Sweden)

    Zoran Kovač

    2018-01-01

    Full Text Available Hydraulic parameters affects behaviour of various ions in soils. The goal of this paper was to get better understanding of relationship between physical and chemical properties and soil permeability at the location of case study profile Velika Gorica, based on the physical and chemical data. Soil profile is situated in the Eutric Cambisol of the Zagreb aquifer, Croatia. Zagreb aquifer represents the only source of potable water for inhabitants of the City of Zagreb and Zagreb County. Based on the data obtained from particle size analysis, soil hydraulic parameters and measured water content, unsaturated hydraulic conductivity values were calculated for the estimation of soil profile permeability. Soil water retention curves and unsaturated hydraulic conductivities are very similar for all depths because soil content does not change significantly through the depth. Determination of anions and cations on soil samples was performed using the method of ion chromatography. Results showed decrease of ions concentrations after 0.6 m depth. SAR distribution in the soil profile shows that SAR values are not significantly changing at the soil profile. The highest CEC and EC values are determined in horizon Bw developed in 0.6 m depth which is consistent with highest SAR value and ions concentrations. All results suggest that physical and chemical properties of investigated profile are in relationship with soil permeability.

  11. Proving relations between modular graph functions

    International Nuclear Information System (INIS)

    Basu, Anirban

    2016-01-01

    We consider modular graph functions that arise in the low energy expansion of the four graviton amplitude in type II string theory. The vertices of these graphs are the positions of insertions of vertex operators on the toroidal worldsheet, while the links are the scalar Green functions connecting the vertices. Graphs with four and five links satisfy several non-trivial relations, which have been proved recently. We prove these relations by using elementary properties of Green functions and the details of the graphs. We also prove a relation between modular graph functions with six links. (paper)

  12. Electrokinetic effects and fluid permeability

    International Nuclear Information System (INIS)

    Berryman, J.G.

    2003-01-01

    Fluid permeability of porous media depends mainly on connectivity of the pore space and two physical parameters: porosity and a pertinent length-scale parameter. Electrical imaging methods typically establish connectivity and directly measure electrical conductivity, which can then often be related to porosity by Archie's law. When electrical phase measurements are made in addition to the amplitude measurements, information about the pertinent length scale can then be obtained. Since fluid permeability controls the ability to flush unwanted fluid contaminants from the subsurface, inexpensive maps of permeability could improve planning strategies for remediation efforts. Detailed knowledge of fluid permeability is also important for oil field exploitation, where knowledge of permeability distribution in three dimensions is a common requirement for petroleum reservoir simulation and analysis, as well as for estimates on the economics of recovery

  13. Relation between histamine release and dye permeability of pulmonary blood-air barrier in x-irradiated rat

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, H [Kobe Univ. (Japan). School of Medicine

    1976-04-01

    The histamine-release kinetics and the influence of released histamine on the permeability of the pulmonary blood-air(BA) barrier during the early period after either whole-body or thoracic x irradiation of the rat were studied. Histamine contents of skin and lung of the irradiated rat decreased rapidly, reaching a minimum at 5 h, and this histamine depletion continued for at least 7 days. Conversely, in circulating blood histamine increased during the early period of 5 h and then decreased gradually. This early increase was linear up to 500R and then became saturated between 500 and 1,000R. Administration of polymixine B (5mg/100g body weight) to rats liberated histamine similarly. Rat sera containg histamine released soon after irradiation enhanced the capillary permeability of Evans blue(EB) in the guinea pig skin reaction, which was effectively countered by pretreatment of the guinea pig with anti-histaminic pyribenzamine (29..mu..g/100g body weight), but not by anti-serotonic chlorpromazine (0.3mg/100g body weight). Similarly, perhaps only the EB-bound serum albumin (EB-albumin), that was seen in alveolar perfusate, penetrated more through the pulmonary BA-barrier with increasing x-ray dose, in parallel with the increase in blood histamine. Pyribenzamine inhibited this effect effectively, but cysteamine (a radical scavenger) did so only partially. Thus, it seems possible that at soon after x irradiation the enhanced permeability of EB-albumin through the BA barrier of rat lung is due preferentially to the pharmacologic action of released histamine and subsidiarily to radiation damage to pulmonary cells.

  14. Discovery of functional and approximate functional dependencies in relational databases

    Directory of Open Access Journals (Sweden)

    Ronald S. King

    2003-01-01

    Full Text Available This study develops the foundation for a simple, yet efficient method for uncovering functional and approximate functional dependencies in relational databases. The technique is based upon the mathematical theory of partitions defined over a relation's row identifiers. Using a levelwise algorithm the minimal non-trivial functional dependencies can be found using computations conducted on integers. Therefore, the required operations on partitions are both simple and fast. Additionally, the row identifiers provide the added advantage of nominally identifying the exceptions to approximate functional dependencies, which can be used effectively in practical data mining applications.

  15. Gut Microbiota Richness and Composition and Dietary Intake of Overweight Pregnant Women Are Related to Serum Zonulin Concentration, a Marker for Intestinal Permeability.

    Science.gov (United States)

    Mokkala, Kati; Röytiö, Henna; Munukka, Eveliina; Pietilä, Sami; Ekblad, Ulla; Rönnemaa, Tapani; Eerola, Erkki; Laiho, Asta; Laitinen, Kirsi

    2016-09-01

    Increased intestinal permeability may precede adverse metabolic conditions. The extent to which the composition of the gut microbiota and diet contribute to intestinal permeability during pregnancy is unknown. The aim was to investigate whether the gut microbiota and diet differ according to serum zonulin concentration, a marker of intestinal permeability, in overweight pregnant women. This cross-sectional study included 100 overweight women [mean age: 29 y; median body mass index (in kg/m(2)): 30] in early pregnancy (zonulin (primary outcome) was determined by using ELISA, gut microbiota by 16S ribosomal RNA sequencing, and dietary intake of macro- and micronutrients from 3-d food diaries. The Mann-Whitney U test was used for pairwise comparisons and linear regression and Spearman's nonparametric correlations for relations between serum zonulin and other outcome variables. Women were divided into "low" (zonulin groups on the basis of the median concentration of zonulin (46.4 ng/mL). The richness of the gut microbiota (Chao 1, observed species and phylogenetic diversity) was higher in the low zonulin group than in the high zonulin group (P = 0.01). The abundances of Bacteroidaceae and Veillonellaceae, Bacteroides and Blautia, and Blautia sp. were lower and of Faecalibacterium and Faecalibacterium prausnitzii higher (P zonulin group than in the high zonulin group. Dietary quantitative intakes of n-3 (ω-3) polyunsaturated fatty acids (PUFAs), fiber, and a range of vitamins and minerals were higher (P zonulin group than those in the high zonulin group. The richness and composition of the gut microbiota and the intake of n-3 PUFAs, fiber, and a range of vitamins and minerals in overweight pregnant women are associated with serum zonulin concentration. Modification of the gut microbiota and diet may beneficially affect intestinal permeability, leading to improved metabolic health of both the mother and fetus. This trial was registered at clinicaltrials.gov as NCT

  16. Lung function declines in patients with pulmonary sarcoidosis and increased respiratory epithelial permeability to 99mTc-DTPA

    International Nuclear Information System (INIS)

    Chinet, T.; Dusser, D.; Labrune, S.; Collignon, M.A.; Chretien, J.; Huchon, G.J.

    1990-01-01

    Respiratory epithelial clearance of 99m Tc-DTPA (RC-Tc-DTPA) and pulmonary function tests (PFT) were determined at intervals of 6 or 12 months in 37 untreated, nonsmoking patients with sarcoidosis over a period of 6 to 36 months. PFT included the measurements of total lung capacity (TLC), vital capacity (VC), FEV1, and diffusing capacity for carbon monoxide. No difference was found between the respiratory clearance of 113m In-DTPA (2.25 +/- 1.00%/min) and RC-Tc-DTPA (2.29 +/- 1.11%/min) in eight patients with pulmonary sarcoidosis. Pulmonary function decreased 15% or more in at least 2 function tests during 11 follow-up periods, but it remained stable during 47 follow-up periods. In patients whose lung function deteriorated, RC-Tc-DTPA increased to 3.51 +/- 1.55%/min; in contrast, in patients whose lung function remained stable, regardless of the initial values, RC-Tc-DTPA was normal (1.00 +/- 0.50%/min; p less than 0.001). In eight patients who were treated with corticosteroids, RC-Tc-DTPA decreased from 3.48 +/- 1.31%/min to 1.56 +/- 0.64%/min (p less than 0.001), and PFT improved. We conclude that in nonsmokers with pulmonary sarcoidosis, increased RC-Tc-DTPA is not related to dissociation of 99mTc from DTPA, RC-Tc-DTPA is increased when pulmonary function decreases, and, when increased, RC-Tc-DTPA decreases with corticosteroid therapy

  17. Effect of sucralfate on gastric permeability in an ex vivo model of stress-related mucosal disease in dogs.

    Science.gov (United States)

    Hill, Tracy L; Lascelles, B Duncan X; Blikslager, Anthony T

    2018-03-01

    Sucralfate is a gastroprotectant with no known systemic effects. The efficacy of sucralfate for prevention and treatment of stress-related mucosal diseases (SRMD) in dogs is unknown. To develop a canine ex vivo model of SRMD and to determine the effect of sucralfate on mucosal barrier function in this model. Gastric antral mucosa was collected immediately postmortem from 29 random-source apparently healthy dogs euthanized at a local animal control facility. Randomized experimental trial. Sucralfate (100 mg/mL) was applied to ex vivo canine gastric mucosa concurrent with and after acid injury. Barrier function was assessed by measurement of transepithelial electrical resistance (TER) and radiolabeled mannitol flux. Application of acidified Ringers solution to the mucosal side of gastric antrum caused a reduction in gastric barrier function, and washout of acidified Ringers solution allowed recovery of barrier function (TER: 34.0 ± 2.8% of control at maximum injury, 71.3 ± 5.5% at recovery, P < .001). Sucralfate application at the time of injury or after injury significantly hastened recovery of barrier function (TER: 118.0 ± 15.2% of control at maximum injury, P < .001 and 111.0 ± 15.5% at recovery, P = .35). Sucralfate appeared effective at restoring defects in gastric barrier function induced by acid and accelerating repair of tissues subjected to acid in this model, suggesting that sucralfate could have utility for the treatment and prevention of SRMD in dogs. Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  18. Effect of Viscous Instability on Unsteady-State Relative Permeability Effet de l'instabilité visqueuse sur la perméabilité relative en régime irrégulier

    Directory of Open Access Journals (Sweden)

    Sarma H. K.

    2006-11-01

    Full Text Available This paper presents the results of an experimental investigation into the relationship between the extent of viscous instability involved in a laboratory displacement and the relative permeability inferred from measured displacement data. Oil displacement experiments were conducted in a triaxially confined silica sand pack. The extent of viscous instability was varied by using mineral oils of different viscosities and by conducting the displacement runs at different flow rates. Relative permeabilities were calculated using both a history matching technique developed by R. M. Sigmund and F. G. McCaffery (8 and an explicit technique suggested by H. K. Sarma and R. G. Bentsen (14. Although, in principle, this explicit technique is similar to the JBN method (11, it is simpler to use in that, it does not require graphical or numerical differentiation of the experimental data. The technique uses two monotonic functional equations, which satisfy all physical conditions that can be imposed on the system, to smooth cumulative oil production and pressure drop histories. Furthermore, these functional equations can also be utilized to predict end-point displacement parameters, such as : Sor and kwor, for displacement experiments which are terminated before reaching the actual end-point. The results show that the two techniques for calculating relative permeabilities from unsteady-state displacement data provide essentially similar results, and that viscous instability significantly affects the relative permeability measurements. The breakthrough recovery, residual oil saturation and the end-point water permeability were all affected by the extent of viscous instability present during the displacement. It was found that these parameters show a systematic dependence on the extent of viscous instability as characterized by the instability number (Isr of E. J. Peters and D. L. Flock (19. Also, the results suggest that the relative permeability curves approach a

  19. Polymeric membrane materials: new aspects of empirical approaches to prediction of gas permeability parameters in relation to permanent gases, linear lower hydrocarbons and some toxic gases.

    Science.gov (United States)

    Malykh, O V; Golub, A Yu; Teplyakov, V V

    2011-05-11

    Membrane gas separation technologies (air separation, hydrogen recovery from dehydrogenation processes, etc.) use traditionally the glassy polymer membranes with dominating permeability of "small" gas molecules. For this purposes the membranes based on the low free volume glassy polymers (e.g., polysulfone, tetrabromopolycarbonate and polyimides) are used. On the other hand, an application of membrane methods for VOCs and some toxic gas recovery from air, separation of the lower hydrocarbons containing mixtures (in petrochemistry and oil refining) needs the membranes with preferable penetration of components with relatively larger molecular sizes. In general, this kind of permeability is characterized for rubbers and for the high free volume glassy polymers. Data files accumulated (more than 1500 polymeric materials) represent the region of parameters "inside" of these "boundaries." Two main approaches to the prediction of gas permeability of polymers are considered in this paper: (1) the statistical treatment of published transport parameters of polymers and (2) the prediction using model of ≪diffusion jump≫ with consideration of the key properties of the diffusing molecule and polymeric matrix. In the frames of (1) the paper presents N-dimensional methods of the gas permeability estimation of polymers using the correlations "selectivity/permeability." It is found that the optimal accuracy of prediction is provided at n=4. In the frames of the solution-diffusion mechanism (2) the key properties include the effective molecular cross-section of penetrating species to be responsible for molecular transportation in polymeric matrix and the well known force constant (ε/k)(eff i) of {6-12} potential for gas-gas interaction. Set of corrected effective molecular cross-section of penetrant including noble gases (He, Ne, Ar, Kr, Xe), permanent gases (H(2), O(2), N(2), CO), ballast and toxic gases (CO(2), NO(,) NO(2), SO(2), H(2)S) and linear lower hydrocarbons (CH(4

  20. Engineering of a novel tri-functional enzyme with MnSOD, catalase and cell-permeable activities.

    Science.gov (United States)

    Luangwattananun, Piriya; Yainoy, Sakda; Eiamphungporn, Warawan; Songtawee, Napat; Bülow, Leif; Ayudhya, Chartchalerm Isarankura Na; Prachayasittikul, Virapong

    2016-04-01

    Cooperative function of superoxide dismutase (SOD) and catalase (CAT), in protection against oxidative stress, is known to be more effective than the action of either single enzyme. Chemical conjugation of the two enzymes resulted in molecules with higher antioxidant activity and therapeutic efficacy. However, chemical methods holds several drawbacks; e.g., loss of enzymatic activity, low homogeneity, time-consuming, and the need of chemical residues removal. Yet, the conjugated enzymes have never been proven to internalize into target cells. In this study, by employing genetic and protein engineering technologies, we reported designing and production of a bi-functional protein with SOD and CAT activities for the first time. To enable cellular internalization, cell penetrating peptide from HIV-1 Tat (TAT) was incorporated. Co-expression of CAT-MnSOD and MnSOD-TAT fusion genes allowed simultaneous self-assembly of the protein sequences into a large protein complex, which is expected to contained one tetrameric structure of CAT, four tetrameric structures of MnSOD and twelve units of TAT. The protein showed cellular internalization and superior protection against paraquat-induced cell death as compared to either complex bi-functional protein without TAT or to native enzymes fused with TAT. This study not only provided an alternative strategy to produce multifunctional protein complex, but also gained an insight into the development of therapeutic agent against oxidative stress-related conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Numerical Aspects Related to the Dynamic Update of Anisotropic Permeability Field During the Transport of Nanoparticles in the Subsurface

    KAUST Repository

    Chen, Meng-Huo; Salama, Amgad; Ei-Amin, Mohamed

    2016-01-01

    Nanoparticles are particles that are between 1 and 100 nanometers in size. They present possible dangers to the environment due to the high surface to volume ratio, which can make the particles very reactive or catalytic. Furthermore, rapid increase in the implementation of nanotechnologies has released large amount of the nanowaste into the environment. In the last two decades, transport of nanoparticles in the subsurface and the potential hazard they impose to the environment have attracted the attention of researchers. In this work, we use numerical simulation to investigate the problem regarding the transport phenomena of nanoparticles in anisotropic porous media. We consider the case in which the permeability in the principal direction components will vary with respect to time. The interesting thing in this case is the fact that the anisotropy could disappear with time. We investigate the effect of the degenerating anisotropy on various fields such as pressure, porosity, concentration and velocities.

  2. Numerical Aspects Related to the Dynamic Update of Anisotropic Permeability Field During the Transport of Nanoparticles in the Subsurface

    KAUST Repository

    Chen, Meng-Huo

    2016-06-01

    Nanoparticles are particles that are between 1 and 100 nanometers in size. They present possible dangers to the environment due to the high surface to volume ratio, which can make the particles very reactive or catalytic. Furthermore, rapid increase in the implementation of nanotechnologies has released large amount of the nanowaste into the environment. In the last two decades, transport of nanoparticles in the subsurface and the potential hazard they impose to the environment have attracted the attention of researchers. In this work, we use numerical simulation to investigate the problem regarding the transport phenomena of nanoparticles in anisotropic porous media. We consider the case in which the permeability in the principal direction components will vary with respect to time. The interesting thing in this case is the fact that the anisotropy could disappear with time. We investigate the effect of the degenerating anisotropy on various fields such as pressure, porosity, concentration and velocities.

  3. Evaluation of the membrane permeability (PAMPA and skin) of benzimidazoles with potential cannabinoid activity and their relation with the Biopharmaceutics Classification System (BCS).

    Science.gov (United States)

    Alvarez-Figueroa, M Javiera; Pessoa-Mahana, C David; Palavecino-González, M Elisa; Mella-Raipán, Jaime; Espinosa-Bustos, Cristián; Lagos-Muñoz, Manuel E

    2011-06-01

    The permeability of five benzimidazole derivates with potential cannabinoid activity was determined in two models of membranes, parallel artificial membrane permeability assay (PAMPA) and skin, in order to study the relationship of the physicochemical properties of the molecules and characteristics of the membranes with the permeability defined by the Biopharmaceutics Classification System. It was established that the PAMPA intestinal absorption method is a good predictor for classifying these molecules as very permeable, independent of their thermodynamic solubility, if and only if these have a Log P(oct) value permeability is conditioned on the solubility of the molecule so that it can only serve as a model for classifying the permeability of molecules that possess high solubility (class I: high solubility, high permeability; class III: high solubility, low permeability).

  4. Phenomenological relation between distribution and fragmentation functions

    International Nuclear Information System (INIS)

    Ma Boqiang; Schmidt, Ivan; Soffer, Jacques; Yang Jianjun

    2002-01-01

    We study the relation between the quark distribution function q(x) and the fragmentation function D q (z) based on a general form D q (x)=C(z)z α q(z) for valence and sea quarks. By adopting two known parametrizations of quark distributions for the proton, we find three simple options for the fragmentation functions that can provide a good description of the available experimental data on proton production in e + e - inelastic annihilation. These three options support the revised Gribov-Lipatov relation D q (z)=zq(z) at z→1, as an approximate relation for the connection between distribution and fragmentation functions. The three options differ in the sea contributions and lead to distinct predictions for antiproton production in the reaction p+p→p-bar+X, thus they are distinguishable in future experiments at RHIC-BNL

  5. Meteoric calcite cementation: diagenetic response to relative fall in sea-level and effect on porosity and permeability, Las Negras area, southeastern Spain

    Science.gov (United States)

    Li, Zhaoqi; Goldstein, Robert H.; Franseen, Evan K.

    2017-03-01

    A dolomitized Upper Miocene carbonate system in southeast Spain contains extensive upper and lower zones of calcite cementation that cut across the stratigraphy. Cement textures including isopachous and circumgranular, which are consistent with phreatic-zone cementation. Cements in the upper cemented zone are non-luminescent, whereas those in the lower cemented zone exhibit multiple bands of luminescent and non-luminescent cements. In the upper cemented zone, isotopic data show two meteoric calcite lines (MCL) with mean δ18O at - 5.1‰ and - 5.8‰ VPDB, whereas no clear MCL is defined in the lower cemented zone where mean δ18O for calcite cement is at - 6.7‰ VPDB. δ13C values in both cement zones are predominantly negative, ranging from - 10 to + 2‰ VPDB, suggestive of carbon from soil gas or decayed organics. Measurements of Tm ice in primary fluid inclusions yield a mode of 0.0 °C in both zones, indicating calcite cementation from fresh water. These two zones define the positions of two different paleo-water tables that formed during a relative sea-level fall and erosional downcutting during the Plio-Pleistocene. The upper cemented zone pre-dated the lower cemented zone on the basis of known relative sea-level history. Meteoric calcite cementation reduced porosity and permeability, but measured values are inconsistent with simple filling of open pore space. Each texture, boundstone, grainstone, packstone, wackestone, produces a different relationship between percent calcite cement and porosity/permeability. Distribution of cements may be predictable on the basis of known sea-level history, and the effect of the cementation can be incorporated into subsurface geomodels by defining surfaces of rock boundaries that separate cemented zones from uncemented zones, and applying texture-specific relationships among cementation, porosity and permeability.

  6. Reconstitution of CO2 Regulation of SLAC1 Anion Channel and Function of CO2-Permeable PIP2;1 Aquaporin as CARBONIC ANHYDRASE4 Interactor

    Science.gov (United States)

    Zeise, Brian; Xu, Danyun; Rappel, Wouter-Jan; Boron, Walter F.; Schroeder, Julian I.

    2016-01-01

    Dark respiration causes an increase in leaf CO2 concentration (Ci), and the continuing increases in atmospheric [CO2] further increases Ci. Elevated leaf CO2 concentration causes stomatal pores to close. Here, we demonstrate that high intracellular CO2/HCO3− enhances currents mediated by the Arabidopsis thaliana guard cell S-type anion channel SLAC1 upon coexpression of any one of the Arabidopsis protein kinases OST1, CPK6, or CPK23 in Xenopus laevis oocytes. Split-ubiquitin screening identified the PIP2;1 aquaporin as an interactor of the βCA4 carbonic anhydrase, which was confirmed in split luciferase, bimolecular fluorescence complementation, and coimmunoprecipitation experiments. PIP2;1 exhibited CO2 permeability. Mutation of PIP2;1 in planta alone was insufficient to impair CO2- and abscisic acid-induced stomatal closing, likely due to redundancy. Interestingly, coexpression of βCA4 and PIP2;1 with OST1-SLAC1 or CPK6/23-SLAC1 in oocytes enabled extracellular CO2 enhancement of SLAC1 anion channel activity. An inactive PIP2;1 point mutation was identified that abrogated water and CO2 permeability and extracellular CO2 regulation of SLAC1 activity. These findings identify the CO2-permeable PIP2;1 as key interactor of βCA4 and demonstrate functional reconstitution of extracellular CO2 signaling to ion channel regulation upon coexpression of PIP2;1, βCA4, SLAC1, and protein kinases. These data further implicate SLAC1 as a bicarbonate-responsive protein contributing to CO2 regulation of S-type anion channels. PMID:26764375

  7. Integrated petrophysical and reservoir characterization workflow to enhance permeability and water saturation prediction

    Science.gov (United States)

    Al-Amri, Meshal; Mahmoud, Mohamed; Elkatatny, Salaheldin; Al-Yousef, Hasan; Al-Ghamdi, Tariq

    2017-07-01

    Accurate estimation of permeability is essential in reservoir characterization and in determining fluid flow in porous media which greatly assists optimize the production of a field. Some of the permeability prediction techniques such as Porosity-Permeability transforms and recently artificial intelligence and neural networks are encouraging but still show moderate to good match to core data. This could be due to limitation to homogenous media while the knowledge about geology and heterogeneity is indirectly related or absent. The use of geological information from core description as in Lithofacies which includes digenetic information show a link to permeability when categorized into rock types exposed to similar depositional environment. The objective of this paper is to develop a robust combined workflow integrating geology and petrophysics and wireline logs in an extremely heterogeneous carbonate reservoir to accurately predict permeability. Permeability prediction is carried out using pattern recognition algorithm called multi-resolution graph-based clustering (MRGC). We will bench mark the prediction results with hard data from core and well test analysis. As a result, we showed how much better improvements are achieved in the permeability prediction when geology is integrated within the analysis. Finally, we use the predicted permeability as an input parameter in J-function and correct for uncertainties in saturation calculation produced by wireline logs using the classical Archie equation. Eventually, high level of confidence in hydrocarbon volumes estimation is reached when robust permeability and saturation height functions are estimated in presence of important geological details that are petrophysically meaningful.

  8. Gill area, permeability and Na+ ,K+ -ATPase activity as a function of size and salinity in the blue crab, Callinectes sapidus.

    Science.gov (United States)

    Li, Tiandao; Roer, Robert; Vana, Matthew; Pate, Susan; Check, Jennifer

    2006-03-01

    Juvenile blue crabs, Callinectes sapidus, extensively utilize oligohaline and freshwater regions of the estuary. With a presumptively larger surface-area-to-body weight ratio, juvenile crabs could experience osmo- and ionoregulatory costs well in excess of that of adults. To test this hypothesis, crabs ranging over three orders of magnitude in body weight were acclimated to either sea water (1,000 mOsm) or dilute sea water (150 mOsm), and gill surface area, water and sodium permeabilities (calculated from the passive efflux of 3H2O and 22Na+), gill Na+, K+ -ATPase activity and expression were measured. Juveniles had a relatively larger gill surface area; weight-specific gill surface area decreased with body weight. Weight-specific water and sodium fluxes also decreased with weight, but not to the same extent as gill surface area; thus juveniles were able to decrease gill permeability slightly more than adults upon acclimation to dilute media. Crabs crabs > 5 g in both posterior and anterior gills. Acclimation to dilute medium induced increased expression of Na+, K+ -ATPase and enzyme activity, but the increase was not as great in juveniles as in larger crabs. The increased weight-specific surface area for water gain and salt loss for small crabs in dilute media presents a challenge that is incompletely compensated by reduced permeability and increased affinity of gill Na+, K+ -ATPase for Na+. Juveniles maintain osmotic and ionic homeostasis by the expression and utilization of extremely high levels of gill Na+, K+ -ATPase, in posterior, as well as in anterior, gills. Copyright 2006 Wiley-Liss, Inc.

  9. Developments in permeable and low permeability barriers

    International Nuclear Information System (INIS)

    Jefferis, S.A.; Norris, G.H.; Thomas, A.O.

    1997-01-01

    The concept of the reactive treatment zone whereby pollutants are attenuated as they move along a pathway in the ground has enabled a re-thinking of many of the concepts of containment. In particular it offers the potential for the control of the flux from a contaminated area by controlling the contaminant concentration in the pathway(s) as well as or instead of using a low permeability barrier. The paper outlines the basic concepts of the reactive treatment zone and the use of permeable and low permeability reactive systems. The paper then gives a case history of the installation of a permeable barrier using an in-situ reaction chamber

  10. Development of vinylic and acetylenic functionalized structures based on high permeable glassy polymers as membrane materials for gas mixtures separation

    Science.gov (United States)

    Roizard, D.; Kiryukhina, Y.; Masalev, A.; Khotimskiy, V.; Teplyakov, V.; Barth, D.

    2013-03-01

    There are several challenging separation problems in industries which can be solved with the help of membrane technologies. It is the case for instance of the purification of gas energy carriers (i.e. H2, CH4) from CO2 as well as the CO2 recovery from flue gas. Glassy polymers containing trimethylsilyl residues like poly(1-trimethylsilyl-1-propyne) [PTMSP] and polyvinyltrimethylsilane [PVTMS] are known to exhibit good membrane properties for gas separation. This paper reports two ways of improving their performances based on the controlled introduction of selective groups - alkyl imidazomium salts (C4I) and polyethyleneglycol (M-PEG)- able to enhance CO2 selectivity. CO2 Isotherm sorption data and permeability measurements have shown that the membrane performances could be significantly improved when C4I and M-PEG were introduced as residues covalently bounded to the main polymer chain. Moreover the introduced bromine reactive centres could also be used to induce chemical crosslinking giving rise to more resistant and stable membranes to organic vapours. With the C4I groups, the CO2 sorption could be enhanced by a factor 4.4.

  11. Cell-permeable Ln(III) chelate-functionalized InP quantum dots as multimodal imaging agents.

    Science.gov (United States)

    Stasiuk, Graeme J; Tamang, Sudarsan; Imbert, Daniel; Poillot, Cathy; Giardiello, Marco; Tisseyre, Céline; Barbier, Emmanuel L; Fries, Pascal Henry; de Waard, Michel; Reiss, Peter; Mazzanti, Marinella

    2011-10-25

    Quantum dots (QDs) are ideal scaffolds for the development of multimodal imaging agents, but their application in clinical diagnostics is limited by the toxicity of classical CdSe QDs. A new bimodal MRI/optical nanosized contrast agent with high gadolinium payload has been prepared through direct covalent attachment of up to 80 Gd(III) chelates on fluorescent nontoxic InP/ZnS QDs. It shows a high relaxivity of 900 mM(-1) s(-1) (13 mM(-1 )s(-1) per Gd ion) at 35 MHz (0.81 T) and 298 K, while the bright luminescence of the QDs is preserved. Eu(III) and Tb(III) chelates were also successfully grafted to the InP/ZnS QDs. The absence of energy transfer between the QD and lanthanide emitting centers results in a multicolor system. Using this convenient direct grafting strategy additional targeting ligands can be included on the QD. Here a cell-penetrating peptide has been co-grafted in a one-pot reaction to afford a cell-permeable multimodal multimeric MRI contrast agent that reports cellular localization by fluorescence and provides high relaxivity and increased tissue retention with respect to commercial contrast agents.

  12. Sugarcane genes related to mitochondrial function

    Directory of Open Access Journals (Sweden)

    Fonseca Ghislaine V.

    2001-01-01

    Full Text Available Mitochondria function as metabolic powerhouses by generating energy through oxidative phosphorylation and have become the focus of renewed interest due to progress in understanding the subtleties of their biogenesis and the discovery of the important roles which these organelles play in senescence, cell death and the assembly of iron-sulfur (Fe/S centers. Using proteins from the yeast Saccharomyces cerevisiae, Homo sapiens and Arabidopsis thaliana we searched the sugarcane expressed sequence tag (SUCEST database for the presence of expressed sequence tags (ESTs with similarity to nuclear genes related to mitochondrial functions. Starting with 869 protein sequences, we searched for sugarcane EST counterparts to these proteins using the basic local alignment search tool TBLASTN similarity searching program run against 260,781 sugarcane ESTs contained in 81,223 clusters. We were able to recover 367 clusters likely to represent sugarcane orthologues of the corresponding genes from S. cerevisiae, H. sapiens and A. thaliana with E-value <= 10-10. Gene products belonging to all functional categories related to mitochondrial functions were found and this allowed us to produce an overview of the nuclear genes required for sugarcane mitochondrial biogenesis and function as well as providing a starting point for detailed analysis of sugarcane gene structure and physiology.

  13. Permeability model of sintered porous media: analysis and experiments

    Science.gov (United States)

    Flórez Mera, Juan Pablo; Chiamulera, Maria E.; Mantelli, Marcia B. H.

    2017-11-01

    In this paper, the permeability of porous media fabricated from copper powder sintering process was modeled and measured, aiming the use of the porosity as input parameter for the prediction of the permeability of sintering porous media. An expression relating the powder particle mean diameter with the permeability was obtained, based on an elementary porous media cell, which is physically represented by a duct formed by the arrangement of spherical particles forming a simple or orthorhombic packing. A circular duct with variable section was used to model the fluid flow within the porous media, where the concept of the hydraulic diameter was applied. Thus, the porous is modeled as a converging-diverging duct. The electrical circuit analogy was employed to determine two hydraulic resistances of the cell: based on the Navier-Stokes equation and on the Darcýs law. The hydraulic resistances are compared between themselves and an expression to determine the permeability as function of average particle diameter is obtained. The atomized copper powder was sifted to reduce the size dispersion of the particles. The porosities and permeabilities of sintered media fabricated from powders with particle mean diameters ranging from 20 to 200 microns were measured, by means of the image analysis method and using an experimental apparatus. The permeability data of a porous media, made of copper powder and saturated with distilled water, was used to compare with the permeability model. Permeability literature models, which considers that powder particles have the same diameter and include porosity data as input parameter, were compared with the present model and experimental data. This comparison showed to be quite good.

  14. Relating Stomatal Conductance to Leaf Functional Traits.

    Science.gov (United States)

    Kröber, Wenzel; Plath, Isa; Heklau, Heike; Bruelheide, Helge

    2015-10-12

    Leaf functional traits are important because they reflect physiological functions, such as transpiration and carbon assimilation. In particular, morphological leaf traits have the potential to summarize plants strategies in terms of water use efficiency, growth pattern and nutrient use. The leaf economics spectrum (LES) is a recognized framework in functional plant ecology and reflects a gradient of increasing specific leaf area (SLA), leaf nitrogen, phosphorus and cation content, and decreasing leaf dry matter content (LDMC) and carbon nitrogen ratio (CN). The LES describes different strategies ranging from that of short-lived leaves with high photosynthetic capacity per leaf mass to long-lived leaves with low mass-based carbon assimilation rates. However, traits that are not included in the LES might provide additional information on the species' physiology, such as those related to stomatal control. Protocols are presented for a wide range of leaf functional traits, including traits of the LES, but also traits that are independent of the LES. In particular, a new method is introduced that relates the plants' regulatory behavior in stomatal conductance to vapor pressure deficit. The resulting parameters of stomatal regulation can then be compared to the LES and other plant functional traits. The results show that functional leaf traits of the LES were also valid predictors for the parameters of stomatal regulation. For example, leaf carbon concentration was positively related to the vapor pressure deficit (vpd) at the point of inflection and the maximum of the conductance-vpd curve. However, traits that are not included in the LES added information in explaining parameters of stomatal control: the vpd at the point of inflection of the conductance-vpd curve was lower for species with higher stomatal density and higher stomatal index. Overall, stomata and vein traits were more powerful predictors for explaining stomatal regulation than traits used in the LES.

  15. Evaluation of the Membrane Permeability (PAMPA and Skin) of Benzimidazoles with Potential Cannabinoid Activity and their Relation with the Biopharmaceutics Classification System (BCS)

    OpenAIRE

    Alvarez-Figueroa, M. Javiera; Pessoa-Mahana, C. David; Palavecino-González, M. Elisa; Mella-Raipán, Jaime; Espinosa-Bustos, Cristián; Lagos-Muñoz, Manuel E.

    2011-01-01

    The permeability of five benzimidazole derivates with potential cannabinoid activity was determined in two models of membranes, parallel artificial membrane permeability assay (PAMPA) and skin, in order to study the relationship of the physicochemical properties of the molecules and characteristics of the membranes with the permeability defined by the Biopharmaceutics Classification System. It was established that the PAMPA intestinal absorption method is a good predictor for classifying thes...

  16. Mitochondrial Function, Dynamics, and Permeability Transition: A Complex Love Triangle as A Possible Target for the Treatment of Brain Aging and Alzheimer's Disease.

    Science.gov (United States)

    Stockburger, Carola; Eckert, Schamim; Eckert, Gunter P; Friedland-Leuner, Kristina; Müller, Walter E

    2018-02-28

    Because of the failure of all amyloid-β directed treatment strategies for Alzheimer's disease (AD), the concept of mitochondrial dysfunction as a major pathomechanism of the cognitive decline in aging and AD has received substantial support. Accordingly, improving mitochondrial function as an alternative strategy for new drug development became of increasing interest and many different compounds have been identified which improve mitochondrial function in preclinical in vitro and in vivo experiments. However, very few if any have been investigated in clinical trials, representing a major drawback of the mitochondria directed drug development. To overcome these problems, we used a top-down approach by investigating several older antidementia drugs with clinical evidence of therapeutic efficacy. These include EGb761® (standardized ginkgo biloba extract), piracetam, and Dimebon. All improve experimentally many aspects of mitochondrial dysfunction including mitochondrial dynamics and also improve cognition and impaired neuronal plasticity, the functionally most relevant consequences of mitochondrial dysfunction. All partially inhibit opening events of the mitochondrial permeability transition pore (mPTP) which previously has mainly been discussed as a mechanism relevant for the induction of apoptosis. However, as more recent work suggests, the mPTP as a master regulator of many mitochondrial functions, our data suggest the mPTP as a possible relevant drug target within the love triangle between mPTP regulation, mitochondrial dynamics, and mitochondrial function including regulation of neuronal plasticity. Drugs interfering with mPTP function will improve not only mitochondrial impairment in aging and AD but also will have beneficial effects on impaired neuronal plasticity, the pathomechanism which correlates best with functional deficits (cognition, behavior) in aging and AD.

  17. Psychophysical function in age-related maculopathy.

    LENUS (Irish Health Repository)

    Neelam, Kumari

    2012-02-01

    Age-related macular degeneration (AMD), the late stage of age-related maculopathy (ARM), is the leading cause of blind registration in developed countries. The visual loss in AMD occurs due to dysfunction and death of photoreceptors (rods and cones) secondary to an atrophic or a neovascular event. The psychophysical tests of vision, which depend on the functional status of the photoreceptors, may detect subtle alterations in the macula before morphological fundus changes are apparent ophthalmoscopically, and before traditional measures of visual acuity exhibit deterioration, and may be a useful tool for assessing and monitoring patients with ARM. Furthermore, worsening of these visual functions over time may reflect disease progression, and some of these, alone or in combination with other parameters, may act as a prognostic indicator for identifying eyes at risk for developing neovascular AMD. Lastly, psychophysical tests often correlate with subjective and relatively undefined symptoms in patients with early ARM, and may reflect limitation of daily activities for ARM patients. However, clinical studies investigating psychophysical function have largely been cross-sectional in nature, with small sample sizes, and lack consistency in terms of the grading and classification of ARM. This article aims to comprehensively review the literature germane to psychophysical tests in ARM, and to furnish the reader with an insight into this complex area of research.

  18. A lattice Boltzmann investigation of steady-state fluid distribution, capillary pressure and relative permeability of a porous medium: Effects of fluid and geometrical properties

    Science.gov (United States)

    Li, Zi; Galindo-Torres, Sergio; Yan, Guanxi; Scheuermann, Alexander; Li, Ling

    2018-06-01

    Simulations of simultaneous steady-state two-phase flow in the capillary force-dominated regime were conducted using the state-of-the-art Shan-Chen multi-component lattice Boltzmann model (SCMC-LBM) based on two-dimensional porous media. We focused on analyzing the fluid distribution (i.e., WP fluid-solid, NP fluid-solid and fluid-fluid interfacial areas) as well as the capillary pressure versus saturation curve which was affected by fluid and geometrical properties (i.e., wettability, adhesive strength, pore size distribution and specific surface area). How these properties influenced the relative permeability versus saturation relation through apparent effective permeability and threshold pressure gradient was also explored. The SCMC-LBM simulations showed that, a thin WP fluid film formed around the solid surface due to the adhesive fluid-solid interaction, resulting in discrete WP fluid distributions and reduction of the WP fluid mobility. Also, the adhesive interaction provided another source of capillary pressure in addition to capillary force, which, however, did not affect the mobility of the NP fluid. The film fluid effect could be enhanced by large adhesive strength and fine pores in heterogeneous porous media. In the steady-state infiltration, not only the NP fluid but also the WP fluid were subjected to the capillary resistance. The capillary pressure effect could be alleviated by decreased wettability, large average pore radius and improved fluid connectivity in heterogeneous porous media. The present work based on the SCMC-LBM investigations elucidated the role of film fluid as well as capillary pressure in the two-phase flow system. The findings have implications for ways to improve the macroscopic flow equation based on balance of force for the steady-state infiltration.

  19. Film Permeability Determination Using Static Permeability Cells

    Science.gov (United States)

    The permeability of tarps to soil fumigant pesticides varies depending on the active ingredient chemical: dimethyl disulfide (DMDS), methyl bromide, chloropicrin, or other. The diffusion rate can be represented by the mass transfer coefficient (MTC).

  20. Clogging in permeable concrete: A review.

    Science.gov (United States)

    Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

    2017-05-15

    Permeable concrete (or "pervious concrete" in North America) is used to reduce local flooding in urban areas and is an important sustainable urban drainage system. However, permeable concrete exhibits reduction in permeability due to clogging by particulates, which severely limits service life. This paper reviews the clogging mechanism and current mitigating strategies in order to inform future research needs. The pore structure of permeable concrete and characteristics of flowing particulates influence clogging, which occurs when particles build-up and block connected porosity. Permeable concrete requires regular maintenance by vacuum sweeping and pressure washing, but the effectiveness and viability of these methods is questionable. The potential for clogging is related to the tortuosity of the connected porosity, with greater tortuosity resulting in increased potential for clogging. Research is required to develop permeable concrete that can be poured on-site, which produces a pore structure with significantly reduced tortuosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Gastrointestinal (GI) permeability correlates with trait anxiety and urinary norepinephrine/creatinine (CR)ratio in children with functional abdominal pain (FAP)and irritable bowel syndrome (IBS) but not in controls

    Science.gov (United States)

    FAP and IBS affect 10–15% of school age children and bear many similarities to irritable bowel syndrome (IBS) in adults (e.g., functional pain, visceral hyperalgesia). Animal models of IBS have suggested a relationship between neonatal stress/anxiety and increased GI permeability later in life. We h...

  2. Permeability log using new lifetime measurements

    International Nuclear Information System (INIS)

    Dowling, D.J.; Boyd, J.F.; Fuchs, J.A.

    1975-01-01

    Comparative measurements of thermal neutron decay time are obtained for a formation after irradiation with a pulsed neutron source. Chloride ions in formation fluids are concentrated by the electrosmosis effect using charged poles on a well logging sonde. The formation is irradiated with fast neutrons and a first comparative measure of the thermal neutron decay time or neutron lifetime is taken. The chloride ions are then dispersed by acoustic pumping with a magnetostrictive transducer. The formation is then again irradiated with fast neutrons and a comparative measure of neutron lifetime is taken. The comparison is a function of the variation in chloride concentration between the two measurements which is related to formation permeability

  3. Suitability of Torrent Permeability Tester to measure air-permeability of covercrete

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, C.; Gonzales-Gasca, C. [Institute of Construction Sciences ' Eduardo Torroja' , Madrid (Spain); Torrent, R. [Portland Cement Institute, (Argentina)

    2000-07-01

    Suitability of the Torrent Permeability Tester (TPT) to measure the permeability of covercrete to air, both in the laboratory and the field, is investigated, and test results obtained in laboratory studies are discussed. The tests performed included the determination of air permeability (TPT method), oxygen permeability (Cembureau method) and capillary suction, rapid chloride permeability test (ASTM C 1202), as well as a one-year carbonation depth test. Concrete specimens of various compositions and curing regimes were used in the tests; the gas-permeability tests were repeated on the same specimens after 28 days, than again at 6 months and 12 months. Test results confirmed the suitability of the TPT as a useful tool in the characterization of the quality the of concrete cover. It was found to be sensitive to changes in concrete quality; repeatable for sensitive properties such as gas permeability ; also, it was found to correlate well with other durability-related properties. 10 refs., 8 tabs., 8 figs.

  4. Enhanced permeability and antifouling performance of cellulose acetate ultrafiltration membrane assisted by l-DOPA functionalized halloysite nanotubes.

    Science.gov (United States)

    Mu, Keguang; Zhang, Dalun; Shao, Ziqiang; Qin, Dujian; Wang, Yalong; Wang, Shuo

    2017-10-15

    l-Dopa functionalized halloysite nanotubes (HNTs) were prepared by the self-polymerization of l-dopa in the weak alkaline condition. Then different contents of l-dopa coated HNTs (LPDHNTs) were blended into cellulose acetate to prepare enhanced performance ultrafiltration membranes via the phase inversion method. The HNTs and LPDHNTs were characterized by FTIR, XPS, and TEM anysis. And the membranes morphologies, separation performance, antifouling performance, mechanical properties and hydrophilicity were also investigated. It was found that the composite membranes exhibited excellent antifouling performance. The pure water flux of 3.0wt% LPDHNTs/CA membrane increased from 11.4Lm -2 h -1 to 92.9Lm -2 h -1 , while the EA rejection ratio of the membrane was about 91.2%. In addition, the mechanical properties of the resultant membranes were strengthened compared with the CA ultrafiltration membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. An experimental study of relative permeability hysteresis, capillary trapping characteristics, and capillary pressure of CO2/brine systems at reservoir conditions

    Science.gov (United States)

    Akbarabadi, Morteza

    We present the results of an extensive experimental study on the effects of hysteresis on permanent capillary trapping and relative permeability of CO2/brine and supercritical (sc)CO2+SO2/brine systems. We performed numerous unsteady- and steady-state drainage and imbibition full-recirculation flow experiments in three different sandstone rock samples, i.e., low and high-permeability Berea, Nugget sandstones, and Madison limestone carbonate rock sample. A state-of-the-art reservoir conditions core-flooding system was used to perform the tests. The core-flooding apparatus included a medical CT scanner to measure in-situ saturations. The scanner was rotated to the horizontal orientation allowing flow tests through vertically-placed core samples with about 3.8 cm diameter and 15 cm length. Both scCO2 /brine and gaseous CO2 (gCO2)/brine fluid systems were studied. The gaseous and supercritical CO2/brine experiments were carried out at 3.46 and 11 MPa back pressures and 20 and 55°C temperatures, respectively. Under the above-mentioned conditions, the gCO2 and scCO2 have 0.081 and 0.393 gr/cm3 densities, respectively. During unsteady-state tests, the samples were first saturated with brine and then flooded with CO2 (drainage) at different maximum flow rates. The drainage process was then followed by a low flow rate (0.375 cm 3/min) imbibition until residual CO2 saturation was achieved. Wide flow rate ranges of 0.25 to 20 cm3/min for scCO2 and 0.125 to 120 cm3min for gCO2 were used to investigate the variation of initial brine saturation (Swi) with maximum CO2 flow rate and variation of trapped CO2 saturation (SCO2r) with Swi. For a given Swi, the trapped scCO2 saturation was less than that of gCO2 in the same sample. This was attributed to brine being less wetting in the presence of scCO2 than in the presence of gCO 2. During the steady-state experiments, after providing of fully-brine saturated core, scCO2 was injected along with brine to find the drainage curve and as

  6. Permeability computation on a REV with an immersed finite element method

    International Nuclear Information System (INIS)

    Laure, P.; Puaux, G.; Silva, L.; Vincent, M.

    2011-01-01

    An efficient method to compute permeability of fibrous media is presented. An immersed domain approach is used to represent the porous material at its microscopic scale and the flow motion is computed with a stabilized mixed finite element method. Therefore the Stokes equation is solved on the whole domain (including solid part) using a penalty method. The accuracy is controlled by refining the mesh around the solid-fluid interface defined by a level set function. Using homogenisation techniques, the permeability of a representative elementary volume (REV) is computed. The computed permeabilities of regular fibre packings are compared to classical analytical relations found in the bibliography.

  7. Permeability prediction in chalks

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Prasad, Manika

    2011-01-01

    The velocity of elastic waves is the primary datum available for acquiring information about subsurface characteristics such as lithology and porosity. Cheap and quick (spatial coverage, ease of measurement) information of permeability can be achieved, if sonic velocity is used for permeability p...... significantly using the effective specific surface as the fluid-flow concept. The FZI unit is appropriate for highly permeable sedimentary rocks such as sandstones and limestones that have small surface areas....

  8. The curvature function in general relativity

    International Nuclear Information System (INIS)

    Hall, G S; MacNay, Lucy

    2006-01-01

    A function, here called the curvature function, is defined and which is constructed explicitly from the type (0, 4) curvature tensor. Although such a function may be defined for any manifold admitting a metric, attention is here concentrated on this function on a spacetime. Some properties of this function are explored and compared with a previous discussion of it given by Petrov

  9. Characterisation and monitoring of the Excavation Disturbed Zone (EDZ) in fractured gneisses of the Roselend underground laboratory: permeability measurements, transport property changes and related radon bursts

    Science.gov (United States)

    Wassermann, Jérôme; Sabroux, Jean-Christophe; Richon, Patrick; Pontreau, Sébastien; Guillon, Sophie; Pili, Eric

    2010-05-01

    The Roselend tunnel was drilled in the fifties by blasting in the micashists, granites and gneisses of the Méraillet massif (French Alps). It is situated on the shore of the Roselend reservoir Lake near its dam. Several tectonic shear fractures related to the Alpine orogeny intersect the dead end tunnel (with length of 128 m and section about 2 m), indeed the fracture density varies from 0.45 to 1 fracture per meter along the tunnel (Dezayes and Villemin 2002). Some fractures are partially or totally filled with secondary minerals. The flow rates of percolating water through the fractured medium are seasonal dependent. Large fractures drain a large fluid volume unlike small ones that drain limited fluid volume (Patriarche et al. 2007). The Roselend underground laboratory allows the study of the geochemical and geophysical responses of a fractured rock mass to periodic sollicitations due to water level variations of the nearby Roselend reservoir Lake. The tunnel was instrumented in the nineties to understand the relationship between radon (Rn-222) concentration and water level variations of the Roselend reservoir Lake (Trique et al. 1999). In order to characterize the geometry and the extent of the EDZ, core drilling and permeability measurements through pneumatic testing are performed along the Roselend tunnel. Drilled core analysis consists of direct observations at a macroscopic scale of fractures (density of fractures from EDZ) and also at a microscopic scale via thin sections. Method of pressure build-up in wells (Jakubick and Franz 1993, Bossart et al. 2002) is used to determine permeability profile along each borehole and hence to precise the extent and geometry of the EDZ. A strong correlation is observed between permeability profiles and the density of fractures estimated from core analysis. The extent of the EDZ appears to be about one tunnel radius i.e. one meter around the tunnel corridor. Another experiment consisting of continuous differential

  10. CDPKs CPK6 and CPK3 function in ABA regulation of guard cell S-type anion- and Ca(2+-permeable channels and stomatal closure.

    Directory of Open Access Journals (Sweden)

    Izumi C Mori

    2006-10-01

    Full Text Available Abscisic acid (ABA signal transduction has been proposed to utilize cytosolic Ca(2+ in guard cell ion channel regulation. However, genetic mutants in Ca(2+ sensors that impair guard cell or plant ion channel signaling responses have not been identified, and whether Ca(2+-independent ABA signaling mechanisms suffice for a full response remains unclear. Calcium-dependent protein kinases (CDPKs have been proposed to contribute to central signal transduction responses in plants. However, no Arabidopsis CDPK gene disruption mutant phenotype has been reported to date, likely due to overlapping redundancies in CDPKs. Two Arabidopsis guard cell-expressed CDPK genes, CPK3 and CPK6, showed gene disruption phenotypes. ABA and Ca(2+ activation of slow-type anion channels and, interestingly, ABA activation of plasma membrane Ca(2+-permeable channels were impaired in independent alleles of single and double cpk3cpk6 mutant guard cells. Furthermore, ABA- and Ca(2+-induced stomatal closing were partially impaired in these cpk3cpk6 mutant alleles. However, rapid-type anion channel current activity was not affected, consistent with the partial stomatal closing response in double mutants via a proposed branched signaling network. Imposed Ca(2+ oscillation experiments revealed that Ca(2+-reactive stomatal closure was reduced in CDPK double mutant plants. However, long-lasting Ca(2+-programmed stomatal closure was not impaired, providing genetic evidence for a functional separation of these two modes of Ca(2+-induced stomatal closing. Our findings show important functions of the CPK6 and CPK3 CDPKs in guard cell ion channel regulation and provide genetic evidence for calcium sensors that transduce stomatal ABA signaling.

  11. Pore network modelling of heavy oil depressurization : a parametric study of factors affecting critical gas saturation and three-phase relative permeabilities

    Energy Technology Data Exchange (ETDEWEB)

    Bondino, I.; McDougall, S.D. [Heriot-Watt Univ., Edinburgh, Scotland (United Kingdom); Hamon, G. [TotalFina Elf Exploration and Production (France)

    2002-07-01

    A review of how the bubble nucleation process affects the efficiency of heavy oil recovery was presented along with a discussion regarding a pore-scale simulator technique to depressurize heavy oil systems. A light oil depressurization simulation is also presented in which a straightforward instantaneous nucleation (IN) model and a more intricate progressive nucleation (PN) model have been used. Simulation results are compared to those derived from the heavy oil systems. The nucleation of bubbles, their growth by solute diffusion and expansion, plus the final stages of coalescence migration and production are the main steps in the depressurization process which were accounted for in a 3-phase simulator. The model can also determine the impact of bubble density and gas-oil diffusion coefficient on critical gas saturation and 3-phase relative permeability. The difference in results for light and heavy oils was also highlighted. In the first scenario, the evolution of gas was characterized by embryonic bubbles that are quickly and randomly nucleated once bubble-point pressure is reached. A stochastic algorithm was developed for PN from experimental observations. IN and PN observations were not necessarily contradictory. It was determined that the high interfacial tension of heavy oils leads to a more compact, capillary-dominated pattern of gas evolution compared to light oils, resulting in improved recoveries for heavy oil systems. 23 refs., 6 tabs., 23 figs.

  12. Event related desynchronisation predicts functional propriospinal myoclonus

    NARCIS (Netherlands)

    Meppelink, A. M.; Little, S.; Oswal, A.; Erro, R.; Kilner, J.; Tijssen, M. A. J.; Brown, P.; Cordovari, C.; Edwards, M.

    2016-01-01

    Objective: Recent diagnostic criteria for functional movement disorders have proposed a "laboratory supported" level of diagnostic certainty where the clinical diagnosis is supported by a positive test. For functional myoclonus the Bereitschaftspotential (BP) is generally accepted as a positive

  13. Experimental study on the response characteristics of coal permeability to pore pressure under loading and unloading conditions

    Science.gov (United States)

    Ye, Zhiwei; Zhang, Lei; Hao, Dingyi; Zhang, Cun; Wang, Chen

    2017-10-01

    In order to study the response characteristics of coal permeability to pore pressure, seepage experiments under different simulated in situ stresses on loading and unloading paths are carried out using the self-developed Gas Flow and Displacement Testing Apparatus (GFDTA) system. Based on the analysis of the experimental data, the relationship between average pore pressure and permeability is found to basically obey the function distribution of a two degree polynomial. In this paper, two aspects of the relationship between permeability and pore pressure are explained: the Klinbenberg effect and expansion, and the penetration of the initial fracture. Under low pore pressure, the decrease in the Klinbenberg effect is the main reason for the decrease in permeability with increased pore pressure. Under relatively high pore pressure, the increase in pore pressure leads to the initial fracture expansion and penetration of the coal sample, which causes an increase in permeability. In order to evaluate the sensitivity of the permeability response to pore pressure changes, the permeability dispersion and pore pressure sensitivity coefficients are defined. After the sensitivity analysis, it was concluded that the loading history changed the fracture structure of the original coal sample and reduced its permeability sensitivity to pore pressure. Under low pore pressure, the Klinbenberg effect is the reason for the decrease in pore pressure sensitivity. Lastly, the permeability-pore pressure relationship is divided into three stages to describe the different response characteristics individually.

  14. Compact rock material gas permeability properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huanling, E-mail: whl_hm@163.com [Key Laboratory of Coastal Disaster and Defence, Ministry of Education, Hohai University, Nanjing 210098 (China); LML, University of Lille, Cite Scientifique, 59655 Villeneuve d’Ascq (France); Xu, Weiya; Zuo, Jing [Institutes of Geotechnical Engineering, Hohai University, Nanjing 210098 (China)

    2014-09-15

    Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO{sub 2,} shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10{sup −19} m{sup 2}; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10{sup −17} m{sup 2}; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure.

  15. Developments in functional equations and related topics

    CERN Document Server

    Ciepliński, Krzysztof; Rassias, Themistocles

    2017-01-01

    This book presents current research on Ulam stability for functional equations and inequalities. Contributions from renowned scientists emphasize fundamental and new results, methods and techniques. Detailed examples are given to theories to further understanding at the graduate level for students in mathematics, physics, and engineering. Key topics covered in this book include: Quasi means Approximate isometries Functional equations in hypergroups Stability of functional equations Fischer-Muszély equation Haar meager sets and Haar null sets Dynamical systems Functional equations in probability theory Stochastic convex ordering Dhombres functional equation Nonstandard analysis and Ulam stability This book is dedicated in memory of Staniłsaw Marcin Ulam, who posed the fundamental problem concerning approximate homomorphisms of groups in 1940; which has provided the stimulus for studies in the stability of functional equations and inequalities.

  16. Gas and Water Permeability of Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Martin, P. L.; Romero, F. J.; Gutierrez-Rodirgo, V.; Barcala, J. M.

    2012-11-01

    The gas pressure of concrete samples was measured in an unsteady-state equipment working under low injection pressures and in a newly fine tuned steady-state setup working under different pressures. These measurements allowed the estimation of the intrinsic and relative gas permeability of the concrete and of the effect of boundary conditions on them. Permeability decreased with water content, but it was also greatly affected by the hydraulic history of concrete, i.e. if it had been previously dried or wetted. In particular, and for a given degree of saturation, the gas permeability of concrete previously saturated was lower than if the concrete had been just air dried or saturated after air drying. In any case, the gas permeability was about two orders of magnitude higher than the liquid water permeability (10-16 vs. 10-18 m2), probably due to the chemical reactions taking place during saturation (carbonation). The relative gas permeability of concrete increased sharply for water degrees of saturation smaller than 50%. The boundary conditions also affected the gas permeability, which seemed to be mostly conditioned by the back pressure and the confining pressure, increasing as the former increased and decreasing as the latter increased, i.e. decreasing as the effective pressure increased. Overall the increase of pressure head or injection pressure implied a decrease in gas permeability. External,microcracking during air-drying could not be ruled out as responsible for the decrease of permeability with confining pressure. The apparent permeability obtained applying the Klinkenberg method for a given effective pressure was only slightly smaller than the average of all the values measured for the same confining pressure range. For this reason it is considered that the Klinkenberg effect was not relevant in the range of pressures applied. (Author) 37 refs.

  17. Permeability of porour rhyolite

    Science.gov (United States)

    Cashman, K.; Rust, A.; Wright, H.; Roberge, J.

    2003-04-01

    The development of permeability in bubble-bearing magmas determines the efficiency of volatile escape during their ascent through volcanic conduits, which, in turn, controls their explosive potential. As permeability requires bubble connectivity, relationships between permeability and porosity in silicic magmas must be controlled by the formation, growth, deformation and coalescence of their constituent bubbles. Although permeability data on porous volcanic pyroclasts are limited, the database can be greatly extended by including data for ceramic and metallic foams1. Several studies indicate that a single number does not adequately describe the permeability of a foam because inertial effects, which predominate at high flow rates, cause deviations from Darcy's law. These studies suggest that permeability is best modeled using the Forschheimer equation to determine both the Darcy permeability (k1) and the non-Darcian (k2) permeability. Importantly, at the high porosities of ceramic foams (75-95%), both k1 and k2 are strongly dependent on pore size and geometry, suggesting that measurement of these parameters provides important information on foam structure. We determined both the connected porosity (by He-pycnometry) and the permeability (k1 and k2) of rhyolitic samples having a wide range in porosity (22-85%) and vesicle textures. In general, these data support previous observations of a power law relationship between connected porosity and Darcy permeability2. In detail, variations in k1 increase at higher porosities. Similarly, k2 generally increases in both mean and standard deviation with increasing porosity. Measurements made on three mutually perpendicular cores from individual pumice clasts suggest that some of the variability can be explained by anisotropy in the vesicle structure. By comparison with ceramic foams, we suggest that the remaining variability results from differences either in average vesicle size or, more likely, in the size of apertures

  18. Relating Functional Groups to the Periodic Table

    Science.gov (United States)

    Struyf, Jef

    2009-01-01

    An introduction to organic chemistry functional groups and their ionic variants is presented. Functional groups are ordered by the position of their specific (hetero) atom in the periodic table. Lewis structures are compared with their corresponding condensed formulas. (Contains 5 tables.)

  19. Cerebral peritumoral oedema study: Does a single dynamic MR sequence assessing perfusion and permeability can help to differentiate glioblastoma from metastasis?

    International Nuclear Information System (INIS)

    Lehmann, Pierre; Saliou, Guillaume; Marco, Giovanni de; Monet, Pauline; Souraya, Stoquart-Elsankari; Bruniau, Alexis; Vallée, Jean Noel; Ducreux, Denis

    2012-01-01

    Our purpose was to differentiate glioblastoma from metastasis using a single dynamic MR sequence to assess perfusion and permeability parameters. 24 patients with glioblastoma or cerebral metastasis with peritumoral oedema were recruited and explored with a 3 T MR unit. Post processing used DPTools software. Regions of interest were drawn around contrast enhancement to assess relative cerebral blood volume and permeability parameters. Around the contrast enhancement Glioblastoma present high rCBV with modification of the permeability, metastasis present slight modified rCBV without modification of permeability. In conclusion, peritumoral T2 hypersignal exploration associating morphological MR and functional MR parameters can help to differentiate cerebral metastasis from glioblastoma.

  20. Soils - Mean Permeability

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital spatial data set provides information on the magnitude and spatial pattern of depth-weighted, mean soil permeability throughout the State of Kansas. The...

  1. Hydrogen permeability through metals

    International Nuclear Information System (INIS)

    Pisarev, A.A.; Tsvetkov, I.V.; Marenkov, E.D.; Yarko, S.S.

    2011-01-01

    The mechanisms of hydrogen permeability through one-layer and multi-layer membranes are considered. The effect of surface roughness, crystal defects, cracks and pores is described. Mathematical description of the processes is given [ru

  2. Permeable pavement study (Edison)

    Data.gov (United States)

    U.S. Environmental Protection Agency — While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types...

  3. Viscous fingering with permeability heterogeneity

    International Nuclear Information System (INIS)

    Tan, C.; Homsy, G.M.

    1992-01-01

    Viscous fingering in miscible displacements in the presence of permeability heterogeneities is studied using two-dimensional simulations. The heterogeneities are modeled as stationary random functions of space with finite correlation scale. Both the variance and scale of the heterogeneities are varied over modest ranges. It is found that the fingered zone grows linearly in time in a fashion analogous to that found in homogeneous media by Tan and Homsy [Phys. Fluids 31, 1330 (1988)], indicating a close coupling between viscous fingering on the one hand and flow through preferentially more permeable paths on the other. The growth rate of the mixing zone increases monotonically with the variance of the heterogeneity, as expected, but shows a maximum as the correlation scale is varied. The latter is explained as a ''resonance'' between the natural scale of fingers in homogeneous media and the correlation scale

  4. A fractal analytical model for the permeabilities of fibrous gas diffusion layer in proton exchange membrane fuel cells

    International Nuclear Information System (INIS)

    Xiao, Boqi; Fan, Jintu; Ding, Feng

    2014-01-01

    The study of water and gas transport through fibrous gas diffusion layer (GDL) is important to the optimization of proton exchange membrane fuel cells (PEMFCs). In this work, analytical models of dimensionless permeability, and water and gas relative permeabilities of fibrous GDL in PEMFCs are derived using fractal theory. In our models, the structure of fibrous GDL is characterized in terms of porosity, tortuosity fractal dimension (D T ), pore area fractal dimensions (d f ), water phase (d f,w ) and gas phase (d f,g ) fractal dimensions. The predicted dimensionless permeability, water and gas relative permeabilities based on the proposed models are in good agreement with experimental data and predictions of numerical simulations reported in the literature. The model reveals that, although water phase and gas phase fractal dimensions strongly depend on porosity, the water and gas relative permeabilities are independent of porosity and are a function of water saturation only. It is also shown that the dimensionless permeability decreases significantly with the increase of tortuosity fractal dimension. On the other hand, there is only a small decrease in the water and gas relative permeabilities when tortuosity fractal dimension increases. One advantage of the proposed analytical model is that it contains no empirical constant, which is normally required in past models

  5. Salt-saturated concrete strength and permeability

    International Nuclear Information System (INIS)

    Pfeifle, T.W.; Hansen, F.D.; Knowles, M.K.

    1996-01-01

    Laboratory-scale experiments applicable to the use of salt-saturated concrete as a seal material for a transuranic waste repository have been completed. Nitrogen gas permeability measurements were made using a flexible-wall permeameter, a confining pressure of 1 MPa, and gas pressure gradients ranging from 0.3 MPa to 0.75 MPa. Results show that salt-saturated concrete has very low intrinsic permeability with values ranging from 9.4 x 10 -22 m 2 to 9.7 x 10 -17 m 2 . Strength and deformation characteristics were investigated under conditions of triaxial compression with confining pressures ranging from 0 to 15 MPa using either axial strain-rate or axial stress-rate control and show that the failure strength of concrete increases with confining pressure which can be adequately described through pressure-sensitive failure criteria. Axial, radial, and volumetric strains were also measured during each test and these data were used to determine elastic properties. Experimental results are applicable in the design and analysis of scale-related functions and apply to other concrete structures subjected to compressive loadings such as dams and prestressed structural members

  6. Determination of glucose exchange rates and permeability of erythrocyte membrane in preeclampsia and subsequent oxidative stress-related protein damage using dynamic-{sup 19}F-NMR

    Energy Technology Data Exchange (ETDEWEB)

    Dickinson, Elizabeth, E-mail: elizabeth.dickinson@york.ac.uk [University of York, Department of Chemistry (United Kingdom); Arnold, John R. P. [Selby College (United Kingdom); Fisher, Julie [University of Leeds, School of Chemistry (United Kingdom)

    2017-02-15

    The cause of the pregnancy condition preeclampsia (PE) is thought to be endothelial dysfunction caused by oxidative stress. As abnormal glucose tolerance has also been associated with PE, we use a fluorinated-mimic of this metabolite to establish whether any oxidative damage to lipids and proteins in the erythrocyte membrane has increased cell membrane permeability. Data were acquired using {sup 19}F Dynamic-NMR (DNMR) to measure exchange of 3-fluoro-3-deoxyglucose (3-FDG) across the membrane of erythrocytes from 10 pregnant women (5 healthy control women, and 5 from women suffering from PE). Magnetisation transfer was measured using the 1D selective inversion and 2D EXSY pulse sequences, over a range of time delays. Integrated intensities from these experiments were used in matrix diagonalisation to estimate the values of the rate constants of exchange and membrane permeability. No significant differences were observed for the rate of exchange of 3-FDG and membrane permeability between healthy pregnant women and those suffering from PE, leading us to conclude that no oxidative damage had occurred at this carrier-protein site in the membrane.

  7. Determination of glucose exchange rates and permeability of erythrocyte membrane in preeclampsia and subsequent oxidative stress-related protein damage using dynamic-"1"9F-NMR

    International Nuclear Information System (INIS)

    Dickinson, Elizabeth; Arnold, John R. P.; Fisher, Julie

    2017-01-01

    The cause of the pregnancy condition preeclampsia (PE) is thought to be endothelial dysfunction caused by oxidative stress. As abnormal glucose tolerance has also been associated with PE, we use a fluorinated-mimic of this metabolite to establish whether any oxidative damage to lipids and proteins in the erythrocyte membrane has increased cell membrane permeability. Data were acquired using "1"9F Dynamic-NMR (DNMR) to measure exchange of 3-fluoro-3-deoxyglucose (3-FDG) across the membrane of erythrocytes from 10 pregnant women (5 healthy control women, and 5 from women suffering from PE). Magnetisation transfer was measured using the 1D selective inversion and 2D EXSY pulse sequences, over a range of time delays. Integrated intensities from these experiments were used in matrix diagonalisation to estimate the values of the rate constants of exchange and membrane permeability. No significant differences were observed for the rate of exchange of 3-FDG and membrane permeability between healthy pregnant women and those suffering from PE, leading us to conclude that no oxidative damage had occurred at this carrier-protein site in the membrane.

  8. Sarcopenia and Age-Related Endocrine Function

    Directory of Open Access Journals (Sweden)

    Kunihiro Sakuma

    2012-01-01

    Full Text Available Sarcopenia, the age-related loss of skeletal muscle, is characterized by a deterioration of muscle quantity and quality leading to a gradual slowing of movement, a decline in strength and power, and an increased risk of fall-related injuries. Since sarcopenia is largely attributed to various molecular mediators affecting fiber size, mitochondrial homeostasis, and apoptosis, numerous targets exist for drug discovery. In this paper, we summarize the current understanding of the endocrine contribution to sarcopenia and provide an update on hormonal intervention to try to improve endocrine defects. Myostatin inhibition seems to be the most interesting strategy for attenuating sarcopenia other than resistance training with amino acid supplementation. Testosterone supplementation in large amounts and at low frequency improves muscle defects with aging but has several side effects. Although IGF-I is a potent regulator of muscle mass, its therapeutic use has not had a positive effect probably due to local IGF-I resistance. Treatment with ghrelin may ameliorate the muscle atrophy elicited by age-dependent decreases in growth hormone. Ghrelin is an interesting candidate because it is orally active, avoiding the need for injections. A more comprehensive knowledge of vitamin-D-related mechanisms is needed to utilize this nutrient to prevent sarcopenia.

  9. Therapeutic benefits of enhancing permeability barrier for atopic eczema

    Directory of Open Access Journals (Sweden)

    George Man

    2015-06-01

    Full Text Available The regulatory role of epidermal permeability barrier function in cutaneous inflammation has been well appreciated. While barrier disruption induces cutaneous inflammation, improvement of permeability barrier function alleviates inflammation. Studies have demonstrated that improvement of epidermal permeability barrier function not only prevents the development of atopic eczema, but also delays the relapse of these diseases. Moreover, enhancing the epidermal permeability barrier also alleviates atopic eczema. Furthermore, co-applications of barrier enhancing products with glucocorticoids can increase the therapeutic efficacy and reduce the adverse effects of glucocorticoids in the treatment of atopic eczema. Therefore, utilization of permeability barrier enhancing products alone or in combination with glucocorticoids could be a valuable approach in the treatment of atopic eczema. In this review, we discuss the benefits of improving the epidermal permeability barrier in the management of atopic eczema.

  10. The complex initial reluctivity, permeability and susceptibility spectra of magnetic materials

    Science.gov (United States)

    Hamilton, N. C.

    2015-03-01

    The HF complex permeability spectrum of a magnetic material is deduced from the measured impedance spectrum, which is then normalized to a series permeability spectrum. However, this series permeability spectrum has previously been shown to correspond to a parallel magnetic circuit, which is not appropriate. Some of the implications of this truth are examined. This electric/magnetic duality has frustrated efforts to interpret the shape of the complex magnetic permeability spectra of materials, and has hindered the application of impedance spectroscopy to magnetic materials. In the presence of magnetic loss, the relationship between the relative magnetic permeability and the magnetic susceptibility is called into question. The use of reluctivity spectra for expressing magnetic material properties is advocated. The relative loss factor, tanδm/μi is shown to be an approximation for the imaginary part of the reluctivity. A single relaxation model for the initial reluctivity spectra of magnetic materials is presented, and its principles are applied to measurements of a high permeability ferrite. The results are presented as contour plots of the spectra as a function of temperature.

  11. Refined functional relations for the elliptic SOS model

    Energy Technology Data Exchange (ETDEWEB)

    Galleas, W., E-mail: w.galleas@uu.nl [ARC Centre of Excellence for the Mathematics and Statistics of Complex Systems, University of Melbourne, VIC 3010 (Australia)

    2013-02-21

    In this work we refine the method presented in Galleas (2012) [1] and obtain a novel kind of functional equation determining the partition function of the elliptic SOS model with domain wall boundaries. This functional relation arises from the dynamical Yang-Baxter relation and its solution is given in terms of multiple contour integrals.

  12. Relations between correlation functions in gauge field theory

    International Nuclear Information System (INIS)

    Simonov, Yu. A.; Shevchenko, V. I.

    1997-01-01

    Exact relations between vacuum correlations of non-Abelian field strengths are obtained. With the aid of exterior differentiation, the invariant parts of a given correlation function are expressed in terms of higher order correlation functions. The corollaries of these relations for the behavior of nonperturbative correlation functions at small and large distances are deduced

  13. Refined functional relations for the elliptic SOS model

    International Nuclear Information System (INIS)

    Galleas, W.

    2013-01-01

    In this work we refine the method presented in Galleas (2012) [1] and obtain a novel kind of functional equation determining the partition function of the elliptic SOS model with domain wall boundaries. This functional relation arises from the dynamical Yang–Baxter relation and its solution is given in terms of multiple contour integrals.

  14. Biostable glucose permeable polymer

    DEFF Research Database (Denmark)

    2017-01-01

    A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

  15. Normal forms for characteristic functions on n-ary relations

    NARCIS (Netherlands)

    D.J.N. van Eijck (Jan)

    2004-01-01

    textabstractFunctions of type (n) are characteristic functions on n-ary relations. Keenan established their importance for natural language semantics, by showing that natural language has many examples of irreducible type (n) functions, i.e., functions of type (n) that cannot be represented as

  16. Permeability of gypsum samples dehydrated in air

    Science.gov (United States)

    Milsch, Harald; Priegnitz, Mike; Blöcher, Guido

    2011-09-01

    We report on changes in rock permeability induced by devolatilization reactions using gypsum as a reference analog material. Cylindrical samples of natural alabaster were dehydrated in air (dry) for up to 800 h at ambient pressure and temperatures between 378 and 423 K. Subsequently, the reaction kinetics, so induced changes in porosity, and the concurrent evolution of sample permeability were constrained. Weighing the heated samples in predefined time intervals yielded the reaction progress where the stoichiometric mass balance indicated an ultimate and complete dehydration to anhydrite regardless of temperature. Porosity showed to continuously increase with reaction progress from approximately 2% to 30%, whilst the initial bulk volume remained unchanged. Within these limits permeability significantly increased with porosity by almost three orders of magnitude from approximately 7 × 10-19 m2 to 3 × 10-16 m2. We show that - when mechanical and hydraulic feedbacks can be excluded - permeability, reaction progress, and porosity are related unequivocally.

  17. Establishment of a permeability/porosity equation for salt grit and damming materials

    International Nuclear Information System (INIS)

    Fein, E.; Mueller-Lyda, I.; Storck, R.

    1996-09-01

    The flow resistance of stowing and sealing materials hinder the transport of brines in an ultimate storage site in salt rock strata. This effect can be seen when brines flow into the storage areas and when contaminated brines are pressed out of the underground structure. The main variable determining flow resistance is permeability. The convergence process induced by rock pressure reduces the size of the available residual cavern and also the permeability of the stowing and sealing materials. In the long-term safety analyses carried out so far, the interdependence between porosity and permeability in the case of salt grit was commonly described by a power function. The present investigation uses the data available until the end of 1994 to derive an improved relation between permeability and porosity for salt grit stowing material. The results obtained show that the power function used until now is still applicable with only a slight modification of parameters. In addition, the statistical distribution functions of the correlated parameters of the permeability/porosity relation were determined for the first time for a probabilistic safety analysis. (orig./DG) [de

  18. Cognitive Function Related to Environmental Exposure to ...

    Science.gov (United States)

    Background: The towns of Marietta and East Liverpool (EL), Ohio, have been identified as having elevated manganese (Mn) in air due to industrial pollution. Objectives: To evaluate relationships between environmental Mn (Mn-air) exposure and distance from the source and cognitive function in residents of two Ohio towns. Methods: Data were obtained from an EPA-sponsored study comparing two towns exposed to Mn-air (Marietta and EL). A cross-sectional design was used. The same inclusion/exclusion criteria and procedures were applied in the two towns. A neuropsychological screening test battery was administered to study participants (EL=86, Marietta=100) which included Stroop Color Word Test, Animal Naming, Auditory Consonant Trigrams (ACT) and Rey-O. To estimate Mn-air, U.S.EPA’s AERMOD dispersion model was used. Distance from source was calculated based on participants’ residential address and air miles from industrial facility emitting Mn-air. A binary logistic regression model controlling for annual household income was used to examine distance from source and neuropsychological outcomes Results: There were no age, sex, or employment status differences between the two towns. Years education was lower in EL (mean (M)=12.9) than Marietta (M=14.6) and years residency in town were higher in EL (M=47.0) than Marietta (M=36.1). EL participants resided closer to the Mn source than Marietta (M=1.12 vs M=4.75 air miles). Mn-air concentrations were higher in EL (M=0

  19. Permeable barrier materials for strontium immobilization: Unsaturated flow apparatus determination of hydraulic conductivity -- Column sorption experiments

    International Nuclear Information System (INIS)

    Moody, T.E.; Conca, J.

    1996-09-01

    Selected materials were tested to emulate a permeable barrier and to examine the (1) capture efficiency of these materials relating to the immobilization of strontium-90 and hexavalent chromium (Cr 6+ ) in Hanford Site groundwater; and (2) hydraulic conductivity of the barrier material relative to the surrounding area. The emplacement method investigated was a permeable reactive barrier to treat contaminated groundwater as it passes through the barrier. The hydraulic conductivity function was measured for each material, and retardation column experiments were performed for each material. Measurements determining the hydraulic conductivity at unsaturated through saturated water content were executed using the Unsaturated Flow Apparatus

  20. Small-bowel permeability in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Madsen, Jan L; Rumessen, Jüri J

    2006-01-01

    Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small-intestinal biopsies......, indicating that CC is a pan-intestinal disease. In small-intestinal disease, the intestinal barrier function may be impaired, and the permeability of the small intestine altered. The purpose of this research was to study small-bowel function in patients with CC as expressed by intestinal permeability....

  1. Concentrations of lipopolysaccharide-binding protein, bactericidal/permeability-increasing protein, soluble CD14 and plasma lipids in relation to endotoxaemia in patients with alcoholic liver disease

    DEFF Research Database (Denmark)

    Schäfer, C.; Parlesak, Alexandr; Schütt, C.

    2002-01-01

    of endotoxin on its target cells (LPS-binding protein and sCD14) were increased. Endotoxin antagonists, such as bactericidal/permeability-increasing protein and high-density lipoprotein, were increased in the pre-cirrhotic stages, whereas a significant reduction of the latter was observed in cirrhosis. Low......-density lipoprotein remained unchanged. The elevation of binding factors in the pre-cirrhotic stages of alcoholic liver disease might attenuate the effects of endotoxaemia, whereas in cirrhosis the reduction of high density lipoprotein, to which large quantities of endotoxin bind, may contribute to its pro...

  2. Negative permeability from random particle composites

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Shahid, E-mail: shussain2@qinetiq.com

    2017-04-15

    Artificial media, such as those composed of periodically-spaced wires for negative permittivity and split ring resonators for negative permeability have been extensively investigated for negative refractive index (NRI) applications (Smith et al., 2004; Pendry et al., 1999) [1,2]. This paper presents an alternative method for producing negative permeability: granular (or particulate) composites incorporating magnetic fillers. Artificial media, such as split-ring resonators, are designed to produce a magnetic resonance feature, which results in negative permeability over a narrow frequency range about the resonance frequency. The position of the feature is dependent upon the size of the inclusion. The material in this case is anisotropic, such that the feature is only observable when the materials are orientated in a specific direction relative to the applied field. A similar resonance can be generated in magnetic granular (particulate) materials: ferromagnetic resonance from the natural spin resonance of particles. Although the theoretical resonance profiles in granular composites shows the permeability dipping to negative values, this is rarely observed experimentally due to resonance damping effects. Results are presented for iron in spherical form and in flake form, dispersed in insulating host matrices. The two particle shapes show different permeability performance, with the magnetic flakes producing a negative contribution. This is attributed to the stronger coupling with the magnetic field resulting from the high aspect ratio of the flakes. The accompanying ferromagnetic resonance is strong enough to overcome the effects of damping and produce negative permeability. The size of random particle composites is not dictated by the wavelength of the applied field, so the materials are potentially much thinner than other, more traditional artificial composites at microwave frequencies. - Highlights: • Negative permeability from random particle composites is

  3. Mechanical and Permeability Characteristics of Latex-Modified Pre-Packed Pavement Repair Concrete as a Function of the Rapid-Set Binder Content

    Directory of Open Access Journals (Sweden)

    Jae-Woong Han

    2015-10-01

    Full Text Available We evaluated the strength and durability characteristics of latex-polymer-modified, pre-packed pavement repair concrete (LMPPRC with a rapid-set binder. The rapid-set binder was a mixture of rapid-set cement and silica sand, where the fluidity was controlled using a latex polymer. The resulting mix exhibited a compressive strength of ¥21 MPa and a flexural strength of ¥3.5 MPa after 4 h of curing (i.e., the traffic opening term for emergency repairs of pavement. The ratio of latex polymer to rapid-set binder material was varied through 0.40, 0.33, 0.29, and 0.25. Mechanical characterization revealed that the mechanical performance, permeability, and impact resistance increased as the ratio of latex polymer to rapid-set binder decreased. The mixture exhibited a compressive strength of ¥21 MPa after 4 h when the ratio of latex polymer to rapid-set binder material was ¤0.29. The mixture exhibited a flexural strength of ¥3.5 MPa after 4 h when the ratio of latex polymer to rapid-set binder material was ¤0.33. The permeability resistance to chloride ions satisfied 2000 C after 7 days of curing for all ratios. The ratio of latex polymer to rapid-set binder material that satisfied all conditions for emergency pavement repair was ¤0.29.

  4. A new water permeability measurement method for unsaturated tight materials using saline solutions

    International Nuclear Information System (INIS)

    Malinsky, Laurent; Talandier, Jean

    2012-01-01

    Document available in extended abstract form only. Relative water permeability of material in a radioactive waste disposal is a key parameter to simulate and predict saturation state evolution. In this paper we present a new measurement method and the results obtained for Callovo-Oxfordian (Cox) clay-stone, host rock of the underground Andra laboratory at Bure (Meuse/Haute-Marne). Relative water permeability of such a low permeability rock as Cox clay-stone has been measured up to now by an indirect method. It consists in submitting a rock sample to successive relative humidity steps imposed by saline solutions. The transient mass variation during each step and the mass at hydric equilibrium are interpreted generally by using an inverse analysis method. The water relative permeability function of water saturation is derived from water diffusion coefficient evolution and water retention curve. The proposed new method consists in directly measuring the water flux across a flat cylindrical submitted to a relative humidity gradient. Two special cells have been developed. The tightness of the lateral sample surface is insured by crushing a polyurethane ring surrounding the sample set in an aluminium device placed over a Plexiglas vessel filled with a saline solution. One of the cells is designed to allow humidity measurement in the cell. These cells can also be used to measure the relative humidity produced by a saline solution or by an unsaturated material. During a permeability measurement, the cell with the sample to be tested is continuously weighted in a Plexiglas box in which a saline solution imposes a different relative humidity at the upper sample face. The experimental set-up is shown on Figure 1. The mean permeability of the sample is proportional to the rate of mass variation when steady state is reached. The result of one test is shown on Figure 2(a). Twenty four permeability measurements have been performed on four argillite samples of 15 mm in height and

  5. Kinetics of the flash-induced P515 response in relation to the H+-permeability of the membrane bound ATPase in spinach chloroplasts

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.L.; van Kooten, O.; Vredenberg, W.J.

    1985-08-01

    The effect of dicyclohexylcarbodiimide (DCCD) on the kinetics of the flash-induced P515 response and on the activity of the ATPase was investigated in isolated spinach chloroplasts. It was found that after the addition of 5 X 10(-8)mol DCCD the rate of ATP hydrolysis induced by a period of 60 sec illumination was decreased to less than 5% of its original value. At this concentration, hardly any effect, if at all, could be detected on the kinetics of the flash-induced P515 response, neither in dark-adapted nor in light-activated chloroplasts. It was concluded that the presence of concentrations of DCCD, sufficiently high to affect the ATPase activity, does not affect the kinetics of the flash-induced P515 response. Since DCCD decreases the H+ permeability of the membrane-bound ATPase, it was concluded that this permeability coefficient for protons is not an important factor in the regulation of the flash-induced membrane potential and, therefore, does not affect the kinetics of the flash-induced P515 response.

  6. Influence of N deficiency and salinity on metal (Pb, Zn and Cu) accumulation and tolerance by Rhizophora stylosa in relation to root anatomy and permeability

    International Nuclear Information System (INIS)

    Cheng Hao; Wang Youshao; Ye Zhihong; Chen Danting; Wang Yutu; Peng Yalan; Wang Liying

    2012-01-01

    Effects of N deficiency and salinity on root anatomy, permeability and metal (Pb, Zn and Cu) translocation and tolerance were investigated using mangrove seedlings of Rhizophora stylosa. The results showed that salt could directly reduce radial oxygen loss (ROL) by stimulation of lignification within exodermis. N deficiency, oppositely, would reduce lignification. Such an alteration in root permeability may also influence metal tolerance by plants. The data indicated that a moderate salinity could stimulate a lignified exodermis that delayed the entry of metals into the roots and thereby contributed to a higher metal tolerance, while N deficiency would aggravate metal toxicity. The results from sand pot trail further confirmed this issue. This study provides a barrier property of the exodermis in dealing with environments. The plasticity of root anatomy is likely an adaptive strategy to regulate the fluxes of gases, nutrients and toxins at root–soil interface. - Highlights: ► Salt induced lignified exodermis which slowed down metal entry into the plants. ► N deficiency, oppositely, aggravated metal mobility and toxicity. ► Barrier properties of the exodermis. - N deficiency and salinity regulate the apoplastic transport barrier of metals and their toxicities

  7. Role of endothelial permeability hotspots and endothelial mitosis in determining age-related patterns of macromolecule uptake by the rabbit aortic wall near branch points.

    Science.gov (United States)

    Chooi, K Yean; Comerford, Andrew; Cremers, Stephanie J; Weinberg, Peter D

    2016-07-01

    Transport of macromolecules between plasma and the arterial wall plays a key role in atherogenesis. Scattered hotspots of elevated endothelial permeability to macromolecules occur in the aorta; a fraction of them are associated with dividing cells. Hotspots occur particularly frequently downstream of branch points, where lesions develop in young rabbits and children. However, the pattern of lesions varies with age, and can be explained by similar variation in the pattern of macromolecule uptake. We investigated whether patterns of hotspots and mitosis also change with age. Evans' Blue dye-labeled albumin was injected intravenously into immature or mature rabbits and its subsequent distribution in the aortic wall around intercostal branch ostia examined by confocal microscopy and automated image analysis. Mitosis was detected by immunofluorescence after adding 5-bromo-2-deoxiuridine to drinking water. Hotspots were most frequent downstream of branches in immature rabbits, but a novel distribution was observed in mature rabbits. Neither pattern was explained by mitosis. Hotspot uptake correlated spatially with the much greater non-hotspot uptake (p hotspots were considered. The pattern of hotspots changes with age. The data are consistent with there being a continuum of local permeabilities rather than two distinct mechanisms. The distribution of the dye, which binds to elastin and collagen, was similar to that of non-binding tracers and to lesions apart from a paucity at the lateral margins of branches that can be explained by lower levels of fibrous proteins in those regions. Copyright © 2016. Published by Elsevier Ireland Ltd.

  8. Relations among several nuclear and electronic density functional reactivity indexes

    Science.gov (United States)

    Torrent-Sucarrat, Miquel; Luis, Josep M.; Duran, Miquel; Toro-Labbé, Alejandro; Solà, Miquel

    2003-11-01

    An expansion of the energy functional in terms of the total number of electrons and the normal coordinates within the canonical ensemble is presented. A comparison of this expansion with the expansion of the energy in terms of the total number of electrons and the external potential leads to new relations among common density functional reactivity descriptors. The formulas obtained provide explicit links between important quantities related to the chemical reactivity of a system. In particular, the relation between the nuclear and the electronic Fukui functions is recovered. The connection between the derivatives of the electronic energy and the nuclear repulsion energy with respect to the external potential offers a proof for the "Quantum Chemical le Chatelier Principle." Finally, the nuclear linear response function is defined and the relation of this function with the electronic linear response function is given.

  9. Relations between the functions of autobiographical memory and psychological wellbeing.

    Science.gov (United States)

    Waters, Theodore E A

    2014-01-01

    Researchers have proposed that autobiographical memory serves three basic functions in everyday life: self-definition, social connection, and directing behaviour (e.g., Bluck, Alea, Habermas, & Rubin, 2005). However, no research has examined relations between the functions of autobiographical memory and healthy functioning (i.e., psychological wellbeing). The present research examined the relations between the self, social, and directive functions of autobiographical memory and three factors of psychological wellbeing in single and recurring autobiographical memories. A total of 103 undergraduate students were recruited and provided ratings of each function for four autobiographical memories (two single, two recurring events). Results found that individuals who use their autobiographical memories to serve self, social, and directive functions reported higher levels of Purpose and Communion and Positive Relationships, and that these relations differ slightly by event type.

  10. Programs for the calculi of blocks permeabilities

    International Nuclear Information System (INIS)

    Gomez Hernandez, J.J.; Sovero Sovero, H.F.

    1993-01-01

    This report studies the stochastic analysis of radionuclide transport. The permeability values of blocks are necessary to do a numeric model for the flux and transport problems in ground soils. The determination of block value by function on grill value is the objective of this program

  11. Controlling DC permeability in cast steels

    International Nuclear Information System (INIS)

    Sumner, Aaran; Gerada, Chris; Brown, Neil; Clare, Adam

    2017-01-01

    Annealing (at multiple cooling rates) and quenching (with tempering) was performed on specimens of cast steel of varying composition. The aim was to devise a method for selecting the steel with the highest permeability, from any given range of steels, and then increasing the permeability by heat treatment. Metallographic samples were imaged using optical microscopy to show the effect of the applied heat treatments on the microstructure. Commonly cast steels can have DC permeability altered by the careful selection of a heat treatment. Increases of up to 381% were achieved by annealing using a cooling rate of 6.0 °C/min. Annealing was found to cause the carbon present in the steel to migrate from grain boundaries and from within ferrite crystals into adjacent pearlite crystals. The migration of the carbon resulted in less carbon at grain boundaries and within ferrite crystals reducing the number of pinning sites between magnetic domains. This gives rise to a higher permeability. Quenching then tempering was found to cause the formation of small ferrite crystals with the carbon content of the steel predominately held in the martensitic crystal structures. The results show that with any given range of steel compositions the highest baseline DC permeability will be found with the steel that has the highest iron content and the lowest carbon content. For the samples tested in this paper a cooling rate of 4.5 °C/min resulted in the relative permeability of the sample with the highest baseline permeability, AS4, increasing from 783 to 1479 at 0.5 T. This paper shows how heat treatments commonly applied to hypoeutectoid cast steels, to improve their mechanical performance, can be used to also enhance electromagnetic properties of these alloys. The use of cast steels allows the creation of DC components for electrical machines not possible by the widely used method of stacking of electrical grade sheet steels. - Highlights: • A range of structural steels had their

  12. Controlling DC permeability in cast steels

    Energy Technology Data Exchange (ETDEWEB)

    Sumner, Aaran, E-mail: aaran.sumner@nottingham.ac.uk [University of Nottingham, Nottingham University Park Campus, Nottingham NG7 2RD, England (United Kingdom); Gerada, Chris, E-mail: chris.gerada@nottingham.ac.uk [Electrical Machines, University of Nottingham, Tower Building, Nottingham NG7 2RD, England (United Kingdom); Brown, Neil, E-mail: neil.brown@cummins.com [Advanced Electrical Machines Research and Technology at Cummins Power Generation, Peterborough PE2 6FZ, England (United Kingdom); Clare, Adam, E-mail: adam.clare@nottingham.ac.uk [Advanced Manufacturing, University of Nottingham, University Park Campus, Nottingham NG7 2RD, England (United Kingdom)

    2017-05-01

    Annealing (at multiple cooling rates) and quenching (with tempering) was performed on specimens of cast steel of varying composition. The aim was to devise a method for selecting the steel with the highest permeability, from any given range of steels, and then increasing the permeability by heat treatment. Metallographic samples were imaged using optical microscopy to show the effect of the applied heat treatments on the microstructure. Commonly cast steels can have DC permeability altered by the careful selection of a heat treatment. Increases of up to 381% were achieved by annealing using a cooling rate of 6.0 °C/min. Annealing was found to cause the carbon present in the steel to migrate from grain boundaries and from within ferrite crystals into adjacent pearlite crystals. The migration of the carbon resulted in less carbon at grain boundaries and within ferrite crystals reducing the number of pinning sites between magnetic domains. This gives rise to a higher permeability. Quenching then tempering was found to cause the formation of small ferrite crystals with the carbon content of the steel predominately held in the martensitic crystal structures. The results show that with any given range of steel compositions the highest baseline DC permeability will be found with the steel that has the highest iron content and the lowest carbon content. For the samples tested in this paper a cooling rate of 4.5 °C/min resulted in the relative permeability of the sample with the highest baseline permeability, AS4, increasing from 783 to 1479 at 0.5 T. This paper shows how heat treatments commonly applied to hypoeutectoid cast steels, to improve their mechanical performance, can be used to also enhance electromagnetic properties of these alloys. The use of cast steels allows the creation of DC components for electrical machines not possible by the widely used method of stacking of electrical grade sheet steels. - Highlights: • A range of structural steels had their

  13. Permeability-Porosity Relationships of Subduction Zone Sediments

    Science.gov (United States)

    Gamage, K.; Screaton, E.; Bekins, B.; Aiello, I.

    2008-12-01

    Permeability-porosity relationships for sediments from Northern Barbados, Costa Rica, Nankai, and Peru subduction zones were examined based on their sediment type and grain size distribution. Greater correlation was observed between permeability and porosity for siliciclastic sediments, diatom oozes, and nannofossil chalk than for nannofossil oozes. For siliciclastic sediments, grouping of sediments by clay content yields relationships that are generally consistent with results from other marine settings and suggest decreasing permeability for a given porosity as clay content increases. Correction of measured porosities for smectite content generally improves the quality of permeability-porosity relationships. The relationship between permeability and porosity for diatom oozes may be controlled by the amount of clay present in the ooze, causing diatom oozes to behave similarly to siliciclastic sediments. For a given porosity the nannofossil oozes have higher permeability values by 1.5 orders of magnitude than the siliciclastic sediments. However, the use of a permeability-porosity relation may not be appropriate for unconsolidated carbonates such as nannofossil oozes. This study provided insight to the effects of porosity correction for smectite, variations in lithology and grain size in permeability-porosity relationships. However, further progress in delineating controls on permeability will require more careful and better documented permeability tests on characterized samples.

  14. Phenomenological structure functions and Gribov-Lipatov relation

    International Nuclear Information System (INIS)

    Choudhary, D.K.; Misra, A.K.

    1987-01-01

    An analysis of the Giribov-Lipatov relation using the phenomenological forms of the structure function F 2 ep is made. The analysis indicate breakdown of the relation at PETRA energies. Plausible reasons of the breakdown of Gribov-Lipatov relation are discussed together with its phenomenological form. 33 refs., 6 figures. (author)

  15. Logarithmically complete monotonicity of a function related to the Catalan-Qi function

    Directory of Open Access Journals (Sweden)

    Qi Feng

    2016-08-01

    Full Text Available In the paper, the authors find necessary and sufficient conditions such that a function related to the Catalan-Qi function, which is an alternative generalization of the Catalan numbers, is logarithmically complete monotonic.

  16. Experimental study of the permeability of concrete under variable thermal and hydric conditions

    International Nuclear Information System (INIS)

    Chen, W.

    2011-01-01

    The main objective of this study is to evaluate the variable thermal and hydric effect, with fissuration effect on the hydraulic behaviour of two concretes. Many experimental tests (saturation and permeability measurements, uniaxial and triaxial compressions tests) were carried out in order to investigate the temperature and saturation influence on the behaviour hydraulic on sound and micro-cracked concrete. Moreover, an experimental device for permeability measurement on macro-cracked concrete was realized, it allows to study the behaviour of macro-cracked of concrete confined and subjected to dry gas flow or very moist air at different temperatures. Multiaxial mechanical tests are coupled to the permeability measurements of sound concrete and micro-cracked by freezing and thawing, which allow to measuring the permeability under deviatoric load-unload with the effect of pre-cracking under stress. We also effectuated a test of relative permeability of concrete as a function of water saturation, subjected to drying and re-saturation, conditioning by the different relative humidity imposed. (author)

  17. An example concerning Sadullaev's boundary relative extremal functions

    OpenAIRE

    Wiegerinck, Jan

    2018-01-01

    We exhibit a smoothly bounded domain $\\Omega$ with the property that for suitable $K\\subset\\partial \\Omega$ and $z\\in \\Omega$ the "Sadullaev boundary relative extremal functions" satisfy the inequality $\\omega_1(z,K,\\Omega)

  18. Orbits in general relativity: the Jacobian elliptic function

    Energy Technology Data Exchange (ETDEWEB)

    Miro Rodriguez, C

    1987-03-11

    The Jacobian elliptic functions are applied to the motion of nonzero-rest-mass particles in the Schwarzschild geometry. The bound and unbound trajectories are analysed together with their classical and special-relativity limits.

  19. Relation between the Fukui function and the Coulomb hole

    Indian Academy of Sciences (India)

    Unknown

    More precisely, in Density Functional The- ory (DFT), the Fukui function f(r) is the derivative of the density ρ(r) relative to the total number of electrons N at constant external potential vext:1,2 f(r) = [∂ρ(r)/∂N]vext. (1). The reactivity of a molecule is more easily discussed by using a discrete index, the condensed Fukui function.

  20. Relation between entropy functional of Keizer and information theory

    International Nuclear Information System (INIS)

    Freidkin, E.S.; Nettleton, R.E.

    1990-01-01

    An equation given by Keizer which relates the second-order functional derivative of the steady-state entropy to the inverse fluctuation correlation function is satisified by the information-theoretic entropy if the equation is extended to arbitrary nonequilibrium states

  1. Study on road surface source pollution controlled by permeable pavement

    Science.gov (United States)

    Zheng, Chaocheng

    2018-06-01

    The increase of impermeable pavement in urban construction not only increases the runoff of the pavement, but also produces a large number of Non-Point Source Pollution. In the process of controlling road surface runoff by permeable pavement, a large number of particulate matter will be withheld when rainwater is being infiltrated, so as to control the source pollution at the source. In this experiment, we determined the effect of permeable road surface to remove heavy pollutants in the laboratory and discussed the related factors that affect the non-point pollution of permeable pavement, so as to provide a theoretical basis for the application of permeable pavement.

  2. Ludic Function of Precedent-Related Phenomena in Media Discourse

    Directory of Open Access Journals (Sweden)

    Yu. M. Velykoroda

    2016-12-01

    Full Text Available The aim of this paper is to determine the ludic function of precedent-related phenomena as a type of intertextuality. The analysis is done on the basis of relevance theoretic approach, through which we aim to show the additional cognitive effect which is created by precedent-related phenomena in media discourse, and this comic effect serves as a foundation for the ludic function of these units.

  3. Application of relative permeability modifier additives to reduce water production in different formations; Aplicacao de aditivos modificadores de permeabilidade relativa para reducao da producao de agua em diferentes formacoes

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Ricardo C.B.; Torres, Ricardo S.; Pedrosa Junior, Helio; Dean, Gregory [BJ Services do Brasil Ltda., RJ (Brazil)

    2004-07-01

    Today most oil companies would be better described as water companies. Total worldwide oil production averages some 75 million barrels per day and, while estimates vary, this is associated with the production of 300 - 400 million barrels of water per day. These values of approximately 5 - 6 barrels of water for every barrel of oil are quite conservative. In the United States, where many fields are depleted, the ratio of water-to-oil production is closer to 9 to 1. In some areas around the world, fields remain on production when the ratio is as high as 48 to 1. Numerous strategies, both mechanical and chemical, have been employed over the years in attempts to achieve reduction in water production. Simple shut-off techniques, using cement, mechanical plugs and cross-linked gels have been widely used. Exotic materials such as DPR (disproportionate permeability reducers) and or new generation of relative permeability modifiers (RPM) have been applied in radial treatments with varying degrees of success. Most recently 'Conformance Fracturing' operations have increased substantially in mature fields as the synergistic effect obtained by adding a RPM to a fracturing fluid have produced increased oil production with reduced water cut in one step, consequently eliminating the cost of additional water shut off treatment later on. This paper presents laboratory testing and worldwide case histories of applications of various RPM materials, at different permeability and temperatures. The paper also describes technical design and operational methodology that we believe to have a significant impact in the development strategies of many fields worldwide. (author)

  4. Permeability measuremens of brazilian Eucalyptus

    Directory of Open Access Journals (Sweden)

    Marcio Rogério da Silva

    2010-09-01

    Full Text Available The permeability of Brazilian Eucalyptus grandis and Eucalyptus citriodora wood was measured in a custom build gas analysis chamber in order to determine which species could be successfully treated with preservatives. Liquid permeability was tested using an emulsion of Neen oil and a control of distillated water. Air was used to test the gas phase permeability. For both Eucalyptus grandis and Eucalyptus citriodora, the longitudinal permeability of gas was shown to be about twice as great as the liquid phase permeability. No radial permeability was observed for either wood. The permeability of air and water through the sapwood of Eucalyptus grandis was greater than that through the sapwood of Eucalyptus citriodora. The permeability of neen oil preservative through the sapwood of Eucalyptus grandis was also greater than through the sapwood of E. Citradora, but the difference was not statistically significant. Scanning Electron Microscopy images showed that the distribution and obstruction in the vessels could be correlated with observed permeability properties. Irrespective of the causes of differences in permeability between the species, the fluid phase flux through the sapwood of both species was significant, indicating that both Eucalyptus grandis and Eucalyptus citriodora could be successfully treated with wood preservative.

  5. Assessment of vascularity and permeability in brain tumor using SPECT and [sup 99m]Tc-DTPA-human serum albumin in relation to [sup 201]Tl SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawara, Jyoji; Fukuoka, Seiji; Takahashi, Shuhei; Takahashi, Masaaki; Satoh, Katsuyasu; Suematsu, Katsumi; Nakamura, Jun-ichi (Nakamura Memorial Hospital, Sapporo (Japan))

    1994-02-01

    Single photon emission computed tomography (SPECT) using technetium-99m-DTPA-human serum albumin ([sup 99m]Tc-HSA-D) and thallium-201 chloride ([sup 201]Tl) was simultaneously performed on 25 patients with brain tumors; 10 with brain metastasis, 8 with astrocytoma (Gr. 3) and 7 with meningioma. The early image was obtained 10 minutes after [sup 99m]Tc-HSA-D (740 MBq) injection, and the delayed image was taken 5 hours after the injection. HSA-D index, based on the ratio of [sup 99m]Tc-HSA-D uptake in the tumor versus the cortical area, was calculated on each image, and compared with Tl index (tumor/contralateral cerebrum ratio). HSA-D delayed index was significantly greater than HSA-D early index in all tumor types (p<0.05 by the Wilcoxon ranked sign test). Linear correlation between HSA-D early index and HSA-D delayed index was significant in astrocytoma (GR. 3) (p<0.01) and meningioma (p<0.001), and a linear correlation between HSA-D delayed index and Tl index was significant in astrocytoma (Gr. 3) (p<0.05). It is concluded that HSA-D early index and delayed index could reflect tumor vascularity and permeability, respectively, and provide supplementary information for Tl index. (author).

  6. Adler Function, DIS sum rules and Crewther Relations

    International Nuclear Information System (INIS)

    Baikov, P.A.; Chetyrkin, K.G.; Kuehn, J.H.

    2010-01-01

    The current status of the Adler function and two closely related Deep Inelastic Scattering (DIS) sum rules, namely, the Bjorken sum rule for polarized DIS and the Gross-Llewellyn Smith sum rule are briefly reviewed. A new result is presented: an analytical calculation of the coefficient function of the latter sum rule in a generic gauge theory in order O(α s 4 ). It is demonstrated that the corresponding Crewther relation allows to fix two of three colour structures in the O(α s 4 ) contribution to the singlet part of the Adler function.

  7. Effects of in Utero Exposure of C57BL/6J Mice to 2,3,7,8-Tetrachlorodibenzo-p-dioxin on Epidermal Permeability Barrier Development and Function

    Science.gov (United States)

    Muenyi, Clarisse S.; Carrion, Sandra Leon; Jones, Lynn A.; Kennedy, Lawrence H.; Slominski, Andrzej T.

    2014-01-01

    Background: Development of the epidermal permeability barrier (EPB) is essential for neonatal life. Defects in this barrier are found in many skin diseases such as atopic dermatitis. Objective: We investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the development and function of the EPB. Methods: Timed-pregnant C57BL/6J mice were gavaged with corn oil or TCDD (10 μg/kg body weight) on gestation day 12. Embryos were harvested on embryonic day (E) 15, E16, E17, and postnatal day (PND) 1. Results: A skin permeability assay showed that TCDD accelerated the development of the EPB, beginning at E15. This was accompanied by a significant decrease in transepidermal water loss (TEWL), enhanced stratification, and formation of the stratum corneum (SC). The levels of several ceramides were significantly increased at E15 and E16. PND1 histology revealed TCDD-induced acanthosis and epidermal hyperkeratosis. This was accompanied by disrupted epidermal tight junction (TJ) function, with increased dye leakage at the terminal claudin-1–staining TJs of the stratum granulosum. Because the animals did not have enhanced rates of TEWL, a commonly observed phenotype in animals with TJ defects, we performed tape-stripping. Removal of most of the SC resulted in a significant increase in TEWL in TCDD-exposed PND1 pups compared with their control group. Conclusions: These findings demonstrate that in utero exposure to TCDD accelerates the formation of an abnormal EPB with leaky TJs, warranting further study of environmental exposures, epithelial TJ integrity, and atopic disease. Citation: Muenyi CS, Leon Carrion S, Jones LA, Kennedy LH, Slominski AT, Sutter CH, Sutter TR. 2014. Effects of in utero exposure of C57BL/6J mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin on epidermal permeability barrier development and function. Environ Health Perspect 122:1052–1058; http://dx.doi.org/10.1289/ehp.1308045 PMID:24904982

  8. Note on asymptotic series expansions for the derivative of the Hurwitz zeta function and related functions

    International Nuclear Information System (INIS)

    Rudaz, S.

    1990-01-01

    Asymptotic series for the Hurwitz zeta function, its derivative, and related functions (including the Riemann zeta function of odd integer argument) are derived as an illustration of a simple, direct method of broad applicability, inspired by the calculus of finite differences

  9. Olfaction Is Related to Motor Function in Older Adults.

    Science.gov (United States)

    Tian, Qu; Resnick, Susan M; Studenski, Stephanie A

    2017-08-01

    Among older adults, both olfaction and motor function predict future cognitive decline and dementia, suggesting potential shared causal pathways. However, it is not known whether olfactory and motor function are independently related in late life. We assessed cross-sectional associations of olfaction with motor and cognitive function, using concurrent data on olfactory function, mobility, balance, fine motor function, manual dexterity, and cognition in 163 Baltimore Longitudinal Study of Aging participants aged 60 and older without common neurological diseases (n = 114 with available cognitive data). Using multiple linear regression, we adjusted for age, sex, race, smoking history, height, and weight for mobility and balance, and education for cognition. We used multiple linear regression to test whether olfaction-motor associations were independent of cognition and depressive symptoms. Olfactory scores were significantly associated with mobility (usual gait speed, rapid gait speed, 400-m walk time, and Health ABC Physical Performance Battery score), balance, fine motor function, and manual dexterity (all p function is associated with mobility, balance, fine motor function, and manual dexterity, and independent of cognitive function, with challenging upper and lower extremity motor function tasks. Longitudinal studies are needed to determine if olfactory performance predicts future mobility and functional decline. Published by Oxford University Press on behalf of The Gerontological Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  10. Approaches to organizing public relations functions in healthcare.

    Science.gov (United States)

    Guy, Bonnie; Williams, David R; Aldridge, Alicia; Roggenkamp, Susan D

    2007-01-01

    This article provides health care audiences with a framework for understanding different perspectives of the role and functions of public relations in healthcare organizations and the resultant alternatives for organizing and enacting public relations functions. Using an example of a current issue receiving much attention in US healthcare (improving rates of organ donation), the article provides examples of how these different perspectives influence public relations goals and objectives, definitions of 'public', activities undertaken, who undertakes them and where they fit into the organizational hierarchy.

  11. Numerical Simulation of Hydraulic Fracturing in Low-/High-Permeability, Quasi-Brittle and Heterogeneous Rocks

    Science.gov (United States)

    Pakzad, R.; Wang, S. Y.; Sloan, S. W.

    2018-04-01

    In this study, an elastic-brittle-damage constitutive model was incorporated into the coupled fluid/solid analysis of ABAQUS to iteratively calculate the equilibrium effective stress of Biot's theory of consolidation. The Young's modulus, strength and permeability parameter of the material were randomly assigned to the representative volume elements of finite element models following the Weibull distribution function. The hydraulic conductivity of elements was associated with their hydrostatic effective stress and damage level. The steady-state permeability test results for sandstone specimens under different triaxial loading conditions were reproduced by employing the same set of material parameters in coupled transient flow/stress analyses of plane-strain models, thereby indicating the reliability of the numerical model. The influence of heterogeneity on the failure response and the absolute permeability was investigated, and the post-peak permeability was found to decrease with the heterogeneity level in the coupled analysis with transient flow. The proposed model was applied to the plane-strain simulation of the fluid pressurization of a cavity within a large-scale block under different conditions. Regardless of the heterogeneity level, the hydraulically driven fractures propagated perpendicular to the minimum principal far-field stress direction for high-permeability models under anisotropic far-field stress conditions. Scattered damage elements appeared in the models with higher degrees of heterogeneity. The partially saturated areas around propagating fractures were simulated by relating the saturation degree to the negative pore pressure in low-permeability blocks under high pressure. By replicating previously reported trends in the fracture initiation and breakdown pressure for different pressurization rates and hydraulic conductivities, the results showed that the proposed model for hydraulic fracture problems is reliable for a wide range of

  12. Constructing and deriving reciprocal trigonometric relations: a functional analytic approach.

    Science.gov (United States)

    Ninness, Chris; Dixon, Mark; Barnes-Holmes, Dermot; Rehfeldt, Ruth Anne; Rumph, Robin; McCuller, Glen; Holland, James; Smith, Ronald; Ninness, Sharon K; McGinty, Jennifer

    2009-01-01

    Participants were pretrained and tested on mutually entailed trigonometric relations and combinatorially entailed relations as they pertained to positive and negative forms of sine, cosine, secant, and cosecant. Experiment 1 focused on training and testing transformations of these mathematical functions in terms of amplitude and frequency followed by tests of novel relations. Experiment 2 addressed training in accordance with frames of coordination (same as) and frames of opposition (reciprocal of) followed by more tests of novel relations. All assessments of derived and novel formula-to-graph relations, including reciprocal functions with diversified amplitude and frequency transformations, indicated that all 4 participants demonstrated substantial improvement in their ability to identify increasingly complex trigonometric formula-to-graph relations pertaining to same as and reciprocal of to establish mathematically complex repertoires.

  13. Active intestinal drug absorption and the solubility-permeability interplay.

    Science.gov (United States)

    Porat, Daniel; Dahan, Arik

    2018-02-15

    The solubility-permeability interplay deals with the question: what is the concomitant effect on the drug's apparent permeability when increasing the apparent solubility with a solubility-enabling formulation? The solubility and the permeability are closely related, exhibit certain interplay between them, and ongoing research throughout the past decade shows that treating the one irrespectively of the other may be insufficient. The aim of this article is to provide an overview of the current knowledge on the solubility-permeability interplay when using solubility-enabling formulations for oral lipophilic drugs, highlighting active permeability aspects. A solubility-enabling formulation may affect the permeability in opposite directions; the passive permeability may decrease as a result of the apparent solubility increase, according to the solubility-permeability tradeoff, but at the same time, certain components of the formulation may inhibit/saturate efflux transporters (when relevant), resulting in significant apparent permeability increase. In these cases, excipients with both solubilizing and e.g. P-gp inhibitory properties may lead to concomitant increase of both the solubility and the permeability. Intelligent development of such formulation will account for the simultaneous effects of the excipients' nature/concentrations on the two arms composing the overall permeability: the passive and the active arms. Overall, thorough mechanistic understanding of the various factors involved in the solubility-permeability interplay may allow developing better solubility-enabling formulations, thereby exploiting the advantages analyzed in this article, offering oral delivery solution even for BCS class IV drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Structure-function relations in physiology education: Where's the mechanism?

    Science.gov (United States)

    Lira, Matthew E; Gardner, Stephanie M

    2017-06-01

    Physiology demands systems thinking: reasoning within and between levels of biological organization and across different organ systems. Many physiological mechanisms explain how structures and their properties interact at one level of organization to produce emergent functions at a higher level of organization. Current physiology principles, such as structure-function relations, selectively neglect mechanisms by not mentioning this term explicitly. We explored how students characterized mechanisms and functions to shed light on how students make sense of these terms. Students characterized mechanisms as 1 ) processes that occur at levels of organization lower than that of functions; and 2 ) as detailed events with many steps involved. We also found that students produced more variability in how they characterized functions compared with mechanisms: students characterized functions in relation to multiple levels of organization and multiple definitions. We interpret these results as evidence that students see mechanisms as holding a more narrow definition than used in the biological sciences, and that students struggle to coordinate and distinguish mechanisms from functions due to cognitive processes germane to learning in many domains. We offer the instructional suggestion that we scaffold student learning by affording students opportunities to relate and also distinguish between these terms so central to understanding physiology. Copyright © 2017 the American Physiological Society.

  15. Permeability of EVOH Barrier Material Used in Automotive Applications: Metrology Development for Model Fuel Mixtures

    Directory of Open Access Journals (Sweden)

    Zhao Jing

    2015-02-01

    Full Text Available EVOH (Ethylene-Vinyl Alcohol materials are widely used in automotive applications in multi-layer fuel lines and tanks owing to their excellent barrier properties to aromatic and aliphatic hydrocarbons. These barrier materials are essential to limit environmental fuel emissions and comply with the challenging requirements of fast changing international regulations. Nevertheless, the measurement of EVOH permeability to model fuel mixtures or to their individual components is particularly difficult due to the complexity of these systems and their very low permeability, which can vary by several orders of magnitude depending on the permeating species and their relative concentrations. This paper describes the development of a new automated permeameter capable of taking up the challenge of measuring minute quantities as low as 1 mg/(m2.day for partial fluxes for model fuel mixtures containing ethanol, i-octane and toluene at 50°C. The permeability results are discussed as a function of the model fuel composition and the importance of EVOH preconditioning is emphasized for accurate permeability measurements. The last part focuses on the influence of EVOH conditioning on its mechanical properties and its microstructure, and further illustrates the specific behavior of EVOH in presence of ethanol oxygenated fuels. The new metrology developed in this work offers a new insight in the permeability properties of a leading barrier material and will help prevent the consequences of (bioethanol addition in fuels on environmental emissions through fuel lines and tanks.

  16. Essential function of linoleic acid esterified in acylglucosylceramide and acylceramide in maintaining the epidermal water permeability barrier. Evidence from feeding studies with oleate, linoleate, arachidonate, columbinate and a-linolenate

    DEFF Research Database (Denmark)

    Hansen, Harald S.; Jensen, B.

    1985-01-01

    sphingolipids. These rats showed increased evaporation which was comparable to that of essential fatty acid-deficient rats. We interpret these results as strong evidence for a very specific and essential function of linoleic acid in maintaining the integrity of the epidermal water permeability barrier......Essential fatty acid-deficient rats were supplemented with 300 mg per day of pure fatty acid esters: oleate (O), linoleate (L), arachidonate (A), and columbinate (C) for 10 days. During this period, the rats in groups L, A, and C all showed a decrease in their initially high trans-epidermal water...... loss, a classical essential fatty acid-deficiency symptom, to a level seen in non-deficient rats (group N). The trans-epidermal water loss in rats of group O was unaffected by the supplementation. Fatty acid composition of two epidermal sphingolipids, acylglucosylceramide and acylceramide, from...

  17. Hand-related physical function in rheumatic hand conditions

    DEFF Research Database (Denmark)

    Klokker, Louise; Terwee, Caroline; Wæhrens, Eva Elisabet Ejlersen

    2016-01-01

    INTRODUCTION: There is no consensus about what constitutes the most appropriate patient-reported outcome measurement (PROM) instrument for measuring physical function in patients with rheumatic hand conditions. Existing instruments lack psychometric testing and vary in feasibility...... and their psychometric qualities. We aim to develop a PROM instrument to assess hand-related physical function in rheumatic hand conditions. METHODS AND ANALYSIS: We will perform a systematic search to identify existing PROMs to rheumatic hand conditions, and select items relevant for hand-related physical function...... as well as those items from the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) item bank that are relevant to patients with rheumatic hand conditions. Selection will be based on consensus among reviewers. Content validity of selected items will be established...

  18. Hand-related physical function in rheumatic hand conditions

    DEFF Research Database (Denmark)

    Klokker, Louise; Terwee, Caroline B; Wæhrens, Eva Ejlersen

    2016-01-01

    as well as those items from the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) item bank that are relevant to patients with rheumatic hand conditions. Selection will be based on consensus among reviewers. Content validity of selected items will be established......INTRODUCTION: There is no consensus about what constitutes the most appropriate patient-reported outcome measurement (PROM) instrument for measuring physical function in patients with rheumatic hand conditions. Existing instruments lack psychometric testing and vary in feasibility...... and their psychometric qualities. We aim to develop a PROM instrument to assess hand-related physical function in rheumatic hand conditions. METHODS AND ANALYSIS: We will perform a systematic search to identify existing PROMs to rheumatic hand conditions, and select items relevant for hand-related physical function...

  19. Relations of mitochondrial genetic variants to measures of vascular function.

    Science.gov (United States)

    Fetterman, Jessica L; Liu, Chunyu; Mitchell, Gary F; Vasan, Ramachandran S; Benjamin, Emelia J; Vita, Joseph A; Hamburg, Naomi M; Levy, Daniel

    2018-05-01

    Mitochondrial genetic variation with resultant alterations in oxidative phosphorylation may influence vascular function and contribute to cardiovascular disease susceptibility. We assessed relations of peptide-encoding variants in the mitochondrial genome with measures of vascular function in Framingham Heart Study participants. Of 258 variants assessed, 40 were predicted to have functional consequences by bioinformatics programs. A maternal pattern of heritability was estimated to contribute to the variability of aortic stiffness. A putative association with a microvascular function measure was identified that requires replication. The methods we have developed can be applied to assess the relations of mitochondrial genetic variation to other phenotypes. Copyright © 2017 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

  20. [Impact of thymic function in age-related immune deterioration].

    Science.gov (United States)

    Ferrando-Martínez, Sara; de la Fuente, Mónica; Guerrero, Juan Miguel; Leal, Manuel; Muñoz-Fernández, M Ángeles

    2013-01-01

    Age-related biological deterioration also includes immune system deterioration and, in consequence, a rise in the incidence and prevalence of infections and cancers, as well as low responses to vaccination strategies. Out of all immune cell subsets, T-lymphocytes seem to be involved in most of the age-related defects. Since T-lymphocytes mature during their passage through the thymus, and the thymus shows an age-related process of atrophy, thymic regression has been proposed as the triggering event of this immune deterioration in elderly people. Historically, it has been accepted that the young thymus sets the T-lymphocyte repertoire during the childhood, whereupon atrophy begins until the elderly thymus is a non-functional evolutionary trace. However, a rising body of knowledge points toward the thymus functioning during adulthood. In the elderly, higher thymic function is associated with a younger immune system, while thymic function failure is associated with all-cause mortality. Therefore, any new strategy focused on the improvement of the elderly quality of life, especially those trying to influence the immune system, should take into account, together with peripheral homeostasis, thymus function as a key element in slowing down age-related decline. Copyright © 2012 SEGG. Published by Elsevier Espana. All rights reserved.

  1. Functional Independent Scaling Relation for ORR/OER Catalysts

    DEFF Research Database (Denmark)

    Christensen, Rune; Hansen, Heine Anton; Dickens, Colin F.

    2016-01-01

    reactions. Here, we show that the oxygen-oxygen bond in the OOH* intermediate is, however, not well described with the previously used class of exchange-correlation functionals. By quantifying and correcting the systematic error, an improved description of gaseous peroxide species versus experimental data...... and a reduction in calculational uncertainty is obtained. For adsorbates, we find that the systematic error largely cancels the vdW interaction missing in the original determination of the scaling relation. An improved scaling relation, which is fully independent of the applied exchange-correlation functional...

  2. Hypergeometric series recurrence relations and some new orthogonal functions

    International Nuclear Information System (INIS)

    Wilson, J.A.

    1978-01-01

    A set of hypergeometric orthogonal polynomials, a set of biorthogonal rational functions generalizing them, and some new three-term relations for hypergeometric series containing properties of these functions are exhibited. The orthogonal polynomials depend on four free parameters, and their orthogonality relations include as special or limiting cases the orthogonalities for the classical polynomials, the Hahn and dual Hahn polynomials, Pollaczek's polynomials orthogonal on an infinite interval, and the 6-j symbols of angular momentum in quantum mechanics. Their properties include a second-order difference equation and a Rodrigues-type formula involving a divided difference operator

  3. Preschooler Sleep Patterns Related to Cognitive and Adaptive Functioning

    Science.gov (United States)

    Keefe-Cooperman, Kathleen; Brady-Amoon, Peggy

    2014-01-01

    Research Findings: Preschoolers' sleep patterns were examined related to cognitive and adaptive functioning. The sample consisted of 874 typically developing preschool children with a mean age of 40.01 months. Parent/caregiver reports of children's sleep pattern factors, Stanford-Binet 5 intelligence scale scores, and Behavior Assessment System…

  4. How Executive Functions Are Related to Intelligence in Williams Syndrome

    Science.gov (United States)

    Osorio, Ana; Cruz, Raquel; Sampaio, Adriana; Garayzabal, Elena; Martinez-Regueiro, Rocio; Goncalves, Oscar F.; Carracedo, Angel; Fernandez-Prieto, Montse

    2012-01-01

    Williams syndrome is characterized by impairments in executive functions (EFs). However, it remains unknown how distinct types of EFs relate to intelligence in this syndrome. The present study analyzed performance on working memory, inhibiting and shifting, and its links to IQ in a sample of 17 individuals with WS, and compared them with a group…

  5. Expression and functional analysis of apoptosis-related gene ...

    African Journals Online (AJOL)

    Administrator

    2011-10-19

    Oct 19, 2011 ... conducted a molecular cloning and functional analysis to study a specific silkworm gene BmICAD related to apoptosis. .... blocking with 5% non-fat milk for 1 h at room temperature, the .... requirements for all next experiments.

  6. The Relational Humor Inventory: Functions of Humor in Close Relationships.

    Science.gov (United States)

    DeKoning, E.; Weiss, R. L.

    2002-01-01

    This study describes the development of a self-report measure of functional humor in relationships. People were asked to report on their own and their partner's use of humor in the marriage. The Relational Humor Inventory proved to be a useful instrument for tapping important positive and negative relationship behaviors. (Contains 30 references, 4…

  7. The Relation between Television Exposure and Executive Function among Preschoolers

    Science.gov (United States)

    Nathanson, Amy I.; Aladé, Fashina; Sharp, Molly L.; Rasmussen, Eric E.; Christy, Katheryn

    2014-01-01

    This study investigated the relations between television exposure during the preschool years and the development of executive function (EF). Data were gathered from 107 parents of preschoolers who provided information on children's television viewing, background television exposure, exposure to specific televised content, and the age at which…

  8. Assessment of biochemical liver function tests in relation to age ...

    African Journals Online (AJOL)

    Background and Objective: Multiorgan failure including liver dysfunction is a common finding in sickle cell anemia (SCA) patients, the cause of which is multifactorial with advancing age said to be a major determinant. There is a paucity of data on liver function among SCA patients in relation to age in northern Nigerian ...

  9. Effect of permeability enhancers on paracellular permeability of acyclovir.

    Science.gov (United States)

    Ates, Muge; Kaynak, Mustafa Sinan; Sahin, Selma

    2016-06-01

    According to Biopharmaceutics Classification System (BCS), acyclovir is a class III (high solubility, low permeability) compound, and it is transported through paracellular route by passive diffusion. The aim of this study was to investigate the effect of various pharmaceutical excipients on the intestinal permeability of acyclovir. The single-pass in-situ intestinal perfusion (SPIP) method was used to estimate the permeability values of acyclovir and metoprolol across different intestinal segments (jejunum, ileum and colon). Permeability coefficient (Peff ) of acyclovir was determined in the absence and presence of a permeation enhancer such as dimethyl β-cyclodextrin (DM-β-CD), sodium lauryl sulfate (SLS), sodium caprate (Cap-Na) and chitosan chloride. All enhancers increased the permeability of paracellularly transported acyclovir. Although Cap-Na has the highest permeability-enhancing effect in all segments, permeation-enhancing effect of chitosan and SLS was only significant in ileum. On the other hand, DM-β-CD slightly decreased the permeability in all intestinal segments. These findings have potential implication concerning the enhancement of absorption of paracellularly transported compounds with limited oral bioavailability. In the case of acyclovir, Cap-Na either alone or in combination with SLS or chitosan has the potential to improve its absorption and bioavailability and has yet to be explored. © 2016 Royal Pharmaceutical Society.

  10. Matrix injection of relative permeability modifier for water control applied in Brazil basins; Injecao matricial de modificadores de permeabilidade relativa para controle de producao de agua aplicado nas bacias petroliferas brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Marchi, Flavio; Stefan, Rodolfo; Mendonca, Paulo; Ferreira, Antonio; Silva, Charles; Fonseca, Ana Isoila [BJ Services do Brasil Ltda., Macae, Rio de Janeiro, RJ (Brazil); Melo, Ricardo C.B. [BJ Services Company Africa Ltd., Angola (Angola)

    2008-07-01

    One of the biggest challenges for the oil industry, even at the beginning of well's production, and principally when the well is producing, is how to reduce and handling the produced water on this process. A conservative estimation says for each barrel of produced oil you have 5 or 6 barrels of formation's water. Some factors must be considerable to establish and maintain a carefully management of this effluent, for example the volume of produced water, which is always growing due to the reservoir maturation and for the secondary recovery process; salt content; residual oil and chemical products presence. Water production is the cause of several problems on wells, like scales, organic deposits or starting the process of formation's sand production induced by fines migration. As a consequence, a cost increment of production is observed due to hydrocarbon/water separation and destination of produced water. The same way, is extremely expensive to manage the even bigger volume, which demands efforts to re-inject the water, treatment which avoid or minimize possible environment impacts, development of new equipment and materials which helps and resists to the effects of produced water. Not inherent reservoir's cause can be several, like bad isolated water zones by cement fail, wrong determination of perforated interval, which is easier to use aid methods. When the water production is directly associated to reservoir, by conning, channeling and/or fingering, generally associated to mobility difference between water and oil, the nowadays most efficient treatment is the injection of relative permeability modifier. This paper will present techniques and results obtained with matrix injection in some fields by the use of the last generation of RPM (relative permeability modifier). (author)

  11. Age-Related Difference in Functional Brain Connectivity of Mastication

    Science.gov (United States)

    Lin, Chia-shu; Wu, Ching-yi; Wu, Shih-yun; Lin, Hsiao-Han; Cheng, Dong-hui; Lo, Wen-liang

    2017-01-01

    The age-related decline in motor function is associated with changes in intrinsic brain signatures. Here, we investigated the functional connectivity (FC) associated with masticatory performance, a clinical index evaluating general masticatory function. Twenty-six older adults (OA) and 26 younger (YA) healthy adults were recruited and assessed using the masticatory performance index (MPI) and resting-state functional magnetic resonance imaging (rs-fMRI). We analyzed the rs-fMRI FC network related to mastication, which was constructed based on 12 bilateral mastication-related brain regions according to the literature. For the OA and the YA group, we identified the mastication-related hubs, i.e., the nodes for which the degree centrality (DC) was positively correlated with the MPI. For each pair of nodes, we identified the inter-nodal link for which the FC was positively correlated with the MPI. The network analysis revealed that, in the YA group, the FC between the sensorimotor cortex, the thalamus (THA) and the cerebellum was positively correlated with the MPI. Consistently, the cerebellum nodes were defined as the mastication-related hubs. In contrast, in the OA group, we found a sparser connection within the sensorimotor regions and cerebellum and a denser connection across distributed regions, including the FC between the superior parietal lobe (SPL), the anterior insula (aINS) and the dorsal anterior cingulate cortex (dACC). Compared to the YA group, the network of the OA group also comprised more mastication-related hubs, which were spatially distributed outside the sensorimotor regions, including the right SPL, the right aINS, and the bilateral dACC. In general, the findings supported the hypothesis that in OA, higher masticatory performance is associated with a widespread pattern of mastication-related hubs. Such a widespread engagement of multiple brain regions associated with the MPI may reflect an increased demand in sensorimotor integration, attentional

  12. On functional relations between reduced distribution functions and entropy production by non-Hamiltonian perturbations

    International Nuclear Information System (INIS)

    Dobbertin, R.

    1976-01-01

    Functional relations are derived which link the reduced distribution functions of a classical N-particle system through the entropy production due to microscopic deviations from hamiltonian dynamics. These relations have been used in an earlier paper for the closure of the BBGKY-hierarchy and may be useful for the establishment of collective particle models in particular and the understanding of irreversibility in general. (Auth.)

  13. A family of tridiagonal pairs and related symmetric functions

    International Nuclear Information System (INIS)

    Baseilhac, Pascal

    2006-01-01

    A family of tridiagonal pairs which appear in the context of quantum integrable systems is studied in detail. The corresponding eigenvalue sequences, eigenspaces and the block tridiagonal structure of their matrix realizations with respect the dual eigenbasis are described. The overlap functions between the two dual bases are shown to satisfy a coupled system of recurrence relations and a set of discrete second-order q-difference equations which generalize those associated with the Askey-Wilson orthogonal polynomials with a discrete argument. Normalizing the fundamental solution to unity, the hierarchies of solutions are rational functions of one discrete argument, explicitly derived in some simplest examples. The weight function which ensures the orthogonality of the system of rational functions defined on a discrete real support is given

  14. Relation between functional mobility and dynapenia in institutionalized frail elderly.

    Science.gov (United States)

    Soares, Antonio Vinicius; Marcelino, Elessandra; Maia, Késsia Cristina; Borges, Noé Gomes

    2017-01-01

    To investigate the relation between functional mobility and dynapenia in institutionalized frail elderly. A descriptive, correlational study involving 26 institutionalized elderly men and women, mean age 82.3±6 years. The instruments employed were the Mini Mental State Examination, the Geriatric Depression Scale, the International Physical Activity Questionnaire, the Timed Up and Go test, a handgrip dynamometer and a portable dynamometer for large muscle groups (shoulder, elbow and hip flexors, knee extensors and ankle dorsiflexors). Significant negative correlation between functional mobility levels assessed by the Timed Up and Go test and dynapenia was observed in all muscle groups evaluated, particularly in knee extensors (r -0.65). A significant negative correlation between muscle strength, particularly knee extensor strength, and functional mobility was found in institutionalized elderly. Data presented indicate that the higher the muscle strength, the shorter the execution time, and this could demonstrate better performance in this functional mobility test.

  15. A family of tridiagonal pairs and related symmetric functions

    Energy Technology Data Exchange (ETDEWEB)

    Baseilhac, Pascal [Laboratoire de Mathematiques et Physique Theorique CNRS/UMR 6083, Federation Denis Poisson, Universite de Tours, Parc de Grandmont, 37200 Tours (France)

    2006-09-22

    A family of tridiagonal pairs which appear in the context of quantum integrable systems is studied in detail. The corresponding eigenvalue sequences, eigenspaces and the block tridiagonal structure of their matrix realizations with respect the dual eigenbasis are described. The overlap functions between the two dual bases are shown to satisfy a coupled system of recurrence relations and a set of discrete second-order q-difference equations which generalize those associated with the Askey-Wilson orthogonal polynomials with a discrete argument. Normalizing the fundamental solution to unity, the hierarchies of solutions are rational functions of one discrete argument, explicitly derived in some simplest examples. The weight function which ensures the orthogonality of the system of rational functions defined on a discrete real support is given.

  16. Functional methods underlying classical mechanics, relativity and quantum theory

    International Nuclear Information System (INIS)

    Kryukov, A

    2013-01-01

    The paper investigates the physical content of a recently proposed mathematical framework that unifies the standard formalisms of classical mechanics, relativity and quantum theory. In the framework states of a classical particle are identified with Dirac delta functions. The classical space is ''made'' of these functions and becomes a submanifold in a Hilbert space of states of the particle. The resulting embedding of the classical space into the space of states is highly non-trivial and accounts for numerous deep relations between classical and quantum physics and relativity. One of the most striking results is the proof that the normal probability distribution of position of a macroscopic particle (equivalently, position of the corresponding delta state within the classical space submanifold) yields the Born rule for transitions between arbitrary quantum states.

  17. State-related functional integration and functional segregation brain networks in schizophrenia.

    Science.gov (United States)

    Yu, Qingbao; Sui, Jing; Kiehl, Kent A; Pearlson, Godfrey; Calhoun, Vince D

    2013-11-01

    Altered topological properties of brain connectivity networks have emerged as important features of schizophrenia. The aim of this study was to investigate how the state-related modulations to graph measures of functional integration and functional segregation brain networks are disrupted in schizophrenia. Firstly, resting state and auditory oddball discrimination (AOD) fMRI data of healthy controls (HCs) and schizophrenia patients (SZs) were decomposed into spatially independent components (ICs) by group independent component analysis (ICA). Then, weighted positive and negative functional integration (inter-component networks) and functional segregation (intra-component networks) brain networks were built in each subject. Subsequently, connectivity strength, clustering coefficient, and global efficiency of all brain networks were statistically compared between groups (HCs and SZs) in each state and between states (rest and AOD) within group. We found that graph measures of negative functional integration brain network and several positive functional segregation brain networks were altered in schizophrenia during AOD task. The metrics of positive functional integration brain network and one positive functional segregation brain network were higher during the resting state than during the AOD task only in HCs. These findings imply that state-related characteristics of both functional integration and functional segregation brain networks are impaired in schizophrenia which provides new insight into the altered brain performance in this brain disorder. © 2013.

  18. A theoretical model for gas permeability in a composite membrane

    International Nuclear Information System (INIS)

    Serrano, D. A

    2009-01-01

    We present in this work an analytical expression for permeability in a two-layer composite membrane, which was derived assuming the same hypothesis as those of Adzumi model for permeability in a homogeneous membrane. Whereas in Adzumi model permeability shows a linear dependence on the mean pressure, our model for a composite membrane related permeability to pressure through a rather complex expression, which covers the whole range of flow, from molecular-Knudsen to viscous-Poiseuille regimes. The expression obtained for permeability contained information of membrane structural properties as pore size, porosity and thickness of each layer, as well as gas nature and operational conditions. Our two-layer-model expression turns into Adzumi formula when the structure of the layers approach to each other. [es

  19. Relation between visual function index and falls-related factors in patients with age-related cataract

    Directory of Open Access Journals (Sweden)

    Mei-Na Huang

    2016-01-01

    Full Text Available AIM:To investigate the relation between vision function index and falls-related factors in patients with age-related cataract.METHODS:Ninety-six patients with age-related cataract were interviewed using a seven-item visual function questionnaire(VF-7, then classified into poor, moderate, or good visual function group. The differences of the three groups on visual acuity, balance and mobility function, cognition, depressive symptoms, self-reported fear of falling were analyzed. RESULTS:The patients in poor visual function group had older age, tendency to depression, was more afraid of falling, compared with groups with higher score in VF-7, and they had worse visual acuity, performed worse on all balance and mobility tests. CONCLUSION:Poor visual function is related to worse visual acuity, weaker balance and mobility performance in patients with age-related cataract. The VF-7, as a simple and convenient self-reported method, can be used as a falling risk monitoring in patients with age-related cataract.

  20. Unsaturated and Saturated Permeabilities of Fiber Reinforcement: Critics and Suggestions

    Directory of Open Access Journals (Sweden)

    Chung Hae ePARK

    2015-04-01

    Full Text Available In general, permeability measurement results show a strong scattering according to the measurement method, the type of test fluid and the fluid injection condition, even though permeability is regarded as a unique property of porous medium. In particular, the discrepancy between the unsaturated and saturated permeabilities for the same fabric has been widely reported. In the literature, relative permeability has been adopted to model the unsaturated flow. This approach has some limits in the modeling of double-scale porosity medium. We address this issue of permeability measurement by rigorously examining the mass conservation condition. Finally, we identify that the pressure gradient is non-linear with positive curvature in the unsaturated flow and a misinterpretation of pressure gradient is the main reason for the difference between the saturated and unsaturated permeabilities of the same fiber reinforcement. We propose to use a fixed value of permeability and to modify the mass conservation equation if there are air voids which are entrapped inside the fiber tow. Finally, we also suggest some guidelines and future perspectives to obtain more consistent permeability measurement results.

  1. Permeability testing of biomaterial membranes

    Energy Technology Data Exchange (ETDEWEB)

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B [NMI Natural and Medical Sciences Institute at University Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen (Germany); Ahlers, M [GELITA AG, Gammelsbacher Str. 2, D-69412 Eberbach (Germany)], E-mail: schlosshauer@nmi.de

    2008-09-01

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation.

  2. Permeability testing of biomaterial membranes

    International Nuclear Information System (INIS)

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B; Ahlers, M

    2008-01-01

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation

  3. Prebiotics as functional food ingredients preventing diet-related diseases.

    Science.gov (United States)

    Florowska, A; Krygier, K; Florowski, T; Dłużewska, E

    2016-05-18

    This paper reviews the potential of prebiotic-containing foods in the prevention or postponement of certain diet-related diseases, such as cardiovascular diseases with hypercholesterolemia, osteoporosis, diabetes, gastrointestinal infections and gut inflammation. Also the data on prebiotics as food ingredients and their impact on food product quality are presented. Prebiotics are short chain carbohydrates that are resistant to the digestion process in the upper part of the digestive system, are not absorbed in any segment of the gastrointestinal system, and finally are selectively fermented by specific genera of colonic bacteria. The mechanisms of the beneficial impacts of prebiotics on human health are very difficult to specify directly, because their health-promoting functions are related to fermentation by intestinal microflora. The impact of prebiotics on diet-related diseases in many ways also depends on the products of their fermentation. Prebiotics as functional food ingredients also have an impact on the quality of food products, due to their textural and gelling properties. Prebiotics as food additives can be very valuable in the creation of functional food aimed at preventing or postponing many diet-related diseases. They additionally have beneficial technological properties which improve the quality of food products.

  4. Mathematical Model to Predict the Permeability of Water Transport in Concrete Structure

    OpenAIRE

    Solomon Ndubuisi Eluozo

    2013-01-01

    Mathematical model to predict the permeability of water transport in concrete has been established, the model is to monitor the rate of water transport in concrete structure. The process of this water transport is based on the constituent in the mixture of concrete. Permeability established a relation on the influence of the micropores on the constituent that made of concrete, the method of concrete placement determine the rate of permeability deposition in concrete structure, permeability es...

  5. ADVANTAGES AND DISADVANTAGES OF MODERN LABORATORY MEASUREMENT OF THE COEFFICIENT OF PERMEABILITY FOR SOIL MATERIALS

    OpenAIRE

    Veinović, Želimir; Kovačević-Zelić, Biljana; Kvasnička, Predrag

    2003-01-01

    Permeability tests are one of the most often performed experiments in geotechnics. Conventional methods conducted by oedometer and triaxial apparatus have many disadvantages, the most significant being the test duration. As a consequence, errors in permeability measurements could occur. On the contrary, by applying modern flow-pump method, permeability measurements can be obtained much more rapidly. Moreover, the permeability/void ratio relation can be obtained by using adequate laboratory de...

  6. Transfer Relations Between Landscape Functions - The Hydrological Point of View

    Science.gov (United States)

    Fohrer, N.; Lenhart, T.; Eckhardt, K.; Frede, H.-G.

    EC market policies and regional subsidy programs have an enormous impact on local land use. This has far reaching consequences on various landscape functions. In the joint research project SFB299 at the Giessen University the effect of land use options on economic, ecological and hydrological landscape functions are under investigation. The continuous time step model SWAT-G (Eckhardt et al., 2000; Arnold et al., 1998) is employed to characterize the influence of land use patterns on hydrological processes. The model was calibrated and validated employing a split sample approach. For two mesoscale watersheds (Aar, 60 km2; Dietzhölze, 81 km2) located in the Lahn-Dill- Bergland, Germany, different land use scenarios were analyzed with regard to their hydrological impact. Additionally the effect of land use change was analyzed with an ecological and an agro-economic model. The impact of the stepwise changing land use was expressed as trade off relations between different landscape functions.

  7. Are we moving towards functioning agricultural markets and trade relations?

    DEFF Research Database (Denmark)

    Brosig, Stephan; Glauben, Thomas; Levkovych, Inna

    2016-01-01

    We introduce a special feature on the functioning of international agricultural markets. This feature is motivated by the increased interest in the functioning of commodity markets raised by unprecedented price turbulences since 2008, major structural changes through changed roles of emerging...... economies and related concerns regarding food security. We argue that the delineation of non-functioning markets from markets that adequately adjusted to adverse framework conditions lacks theoretical foundation. We discuss the relevance of some results on institutions for agricultural markets in emerging...... and transition countries. A synthesis of the articles included in the special feature is provided by highlighting the selection of topics that span a topical range covering price formation on world and domestic markets, market power and trade policy modelling....

  8. Cone pathway function in relation to asymmetric carotid artery stenosis

    DEFF Research Database (Denmark)

    Kofoed, Peter Kristian; Munch, Inger Christine; Holfort, Stig K

    2013-01-01

    Purpose:  To examine retinal function in relation to retinal perfusion pressure in patients with carotid artery stenosis. Methods:  Thirteen patients with carotid artery stenosis without clinical eye disease underwent assessment of ophthalmic artery systolic blood pressure (OSP) by ocular...... pneumoplethysmography, carotid artery obstructive disease by ultrasonography, intraocular pressure by applanation tonometry, retinal perfusion by fluorescein angiography and retinal function by multifocal electroretinography (mfERG). Data analysis compared the eye on the most stenotic side with the fellow eye...... pressure (p = 0.0028, 0.011, 0.041 for N1, P1, N2 implicit times, respectively, and p = 0.0086, 0.016, 0.040 for N1, P1, N2 for amplitudes, respectively, corrected for OSP). Conclusion:  Cone function deviation was observed in clinically healthy eyes on the side with highest degree of carotid artery...

  9. Learning related modulation of functional retrieval networks in man.

    Science.gov (United States)

    Petersson, K M; Sandblom, J; Gisselgård, J; Ingvar, M

    2001-07-01

    The medial temporal lobe has been implicated in studies of episodic memory tasks involving spatio-temporal context and object-location conjunctions. We have previously demonstrated that an increased level of practice in a free-recall task parallels a decrease in the functional activity of several brain regions, including the medial temporal lobe, the prefrontal, the anterior cingulate, the anterior insular, and the posterior parietal cortices, that in concert demonstrate a move from elaborate controlled processing towards a higher degree of automaticity. Here we report data from two experiments that extend these initial observations. We used a similar experimental approach but probed for effects of retrieval paradigms and stimulus material. In the first experiment we investigated practice related changes during recognition of object-location conjunctions and in the second during free-recall of pseudo-words. Learning in a neural network is a dynamic consequence of information processing and network plasticity. The present and previous PET results indicate that practice can induce a learning related functional restructuring of information processing. Different adaptive processes likely subserve the functional re-organisation observed. These may in part be related to different demands for attentional and working memory processing. It appears that the role(s) of the prefrontal cortex and the medial temporal lobe in memory retrieval are complex, perhaps reflecting several different interacting processes or cognitive components. We suggest that an integrative interactive perspective on the role of the prefrontal and medial temporal lobe is necessary for an understanding of the processing significance of these regions in learning and memory. It appears necessary to develop elaborated and explicit computational models for prefrontal and medial temporal functions in order to derive detailed empirical predictions, and in combination with an efficient use and development of

  10. The use of generalized functions and distributions in general relativity

    International Nuclear Information System (INIS)

    Steinbauer, R; Vickers, J A

    2006-01-01

    We review the extent to which one can use classical distribution theory in describing solutions of Einstein's equations. We show that there are a number of physically interesting cases which cannot be treated using distribution theory but require a more general concept. We describe a mathematical theory of nonlinear generalized functions based on Colombeau algebras and show how this may be applied in general relativity. We end by discussing the concept of singularity in general relativity and show that certain solutions with weak singularities may be regarded as distributional solutions of Einstein's equations. (topical review)

  11. Relation between functional mobility and dynapenia in institutionalized frail elderly

    OpenAIRE

    Soares, Antonio Vinicius; Marcelino, Elessandra; Maia, Késsia Cristina; Borges, Noé Gomes

    2017-01-01

    ABSTRACT Objective To investigate the relation between functional mobility and dynapenia in institutionalized frail elderly. Methods A descriptive, correlational study involving 26 institutionalized elderly men and women, mean age 82.3±6 years. The instruments employed were the Mini Mental State Examination, the Geriatric Depression Scale, the International Physical Activity Questionnaire, the Timed Up and Go test, a handgrip dynamometer and a portable dynamometer for large muscle groups (sho...

  12. Relation between functional mobility and dynapenia in institutionalized frail elderly

    OpenAIRE

    Soares, Antonio Vinicius; Marcelino, Elessandra; Maia, Késsia Cristina; Borges Junior, Noé Gomes

    2017-01-01

    ABSTRACT Objective To investigate the relation between functional mobility and dynapenia in institutionalized frail elderly. Methods A descriptive, correlational study involving 26 institutionalized elderly men and women, mean age 82.3±6 years. The instruments employed were the Mini Mental State Examination, the Geriatric Depression Scale, the International Physical Activity Questionnaire, the Timed Up and Go test, a handgrip dynamometer and a portable dynamometer for large muscle groups ...

  13. Narcissistic personality disorder: relations with distress and functional impairment.

    Science.gov (United States)

    Miller, Joshua D; Campbell, W Keith; Pilkonis, Paul A

    2007-01-01

    This study examined the construct validity of narcissistic personality disorder (NPD) by examining the relations between NPD and measures of psychologic distress and functional impairment both concurrently and prospectively across 2 samples. In particular, the goal was to address whether NPD typically "meets" criterion C of the DSM-IV definition of Personality Disorder, which requires that the symptoms lead to clinically significant distress or impairment in functioning. Sample 1 (n = 152) was composed of individuals receiving psychiatric treatment, whereas sample 2 (n = 151) was composed of both psychiatric patients (46%) and individuals from the community. Narcissistic personality disorder was linked to ratings of depression, anxiety, and several measures of impairment both concurrently and at 6-month follow-up. However, the relations between NPD and psychologic distress were (a) small, especially in concurrent measurements, and (b) largely mediated by impaired functioning. Narcissistic personality disorder was most strongly related to causing pain and suffering to others, and this relationship was significant even when other Cluster B personality disorders were controlled. These findings suggest that NPD is a maladaptive personality style which primarily causes dysfunction and distress in interpersonal domains. The behavior of narcissistic individuals ultimately leads to problems and distress for the narcissistic individuals and for those with whom they interact.

  14. Vitamin B12 Deficiency in Relation to Functional Disabilities

    Directory of Open Access Journals (Sweden)

    Heather E. Rasmussen

    2013-11-01

    Full Text Available This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12 deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999–2002 National Health and Nutrition Examination Surveys (NHANES were categorized in relation to three previously used definitions of B12 deficiency: (1 serum B12 20 μmol/L; and (3 serum B12 0.21 μmol/L. Functional measures of peripheral neuropathy, balance, cognitive function, gait speed, along with self-reported disability (including activities of daily living were examined with standardized instruments by trained NHANES interviewers and technicians. Individuals identified as B12 deficient by definition 2 were more likely to manifest peripheral neuropathy OR (odds (95% confidence intervals, p value: 9.70 (2.24, 42.07, 0.004 and report greater total disability, 19.61 (6.22, 61.86 0.0001 after adjustments for age, sex, race, serum creatinine, and ferritin concentrations, smoking, diabetes, and peripheral artery disease. Smaller, but significantly increased, odds of peripheral neuropathy and total disability were also observed when definition 3 was applied. Functional measures and reported disabilities were associated with B12 deficiency definitions that include B12 biomarkers (homocysteine or methylmalonic acid. Further study of these definitions is needed to alert clinicians of possible subclinical B12 deficiency because functional decline amongst older adults may be correctable if the individual is B12 replete.

  15. Geothermal Permeability Enhancement - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Joe Beall; Mark Walters

    2009-06-30

    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  16. Family functioning in paediatric obsessive compulsive and related disorders.

    Science.gov (United States)

    Murphy, Yolanda E; Flessner, Christopher A

    2015-11-01

    Research among youths with obsessive compulsive disorder (OCD) has shown a significant relationship between illness severity, treatment outcome, and the family environment yet little work has been undertaken among the broader class of obsessive compulsive and related disorders (OCRDs) - Trichotillomania, body dysmorphic disorder (BDD), skin picking disorder (SPD), and hoarding. The aim of this study was to (1) review the family functioning literature among paediatric OCRDs, (2) address limitations to previous studies, and (3) highlight areas in need of further research. A review of the literature was conducted using several databases (i.e., Google Scholar, PubMed, ScienceDirect) and employing key search terms (e.g., 'family functioning', 'paediatric OCD'). The resultant articles examined several domains subsumed under the broader heading of family environment including parental mental health, parenting practices, family dynamics, family involvement with symptoms, and family emotional climate. The literature reviewed demonstrated a strong relationship between paediatric OCD and adverse family functioning (e.g., parental symptoms of anxiety and depression, family accommodation, family strain and stress, parental guilt and fear) in all identified domains. While family functioning research in paediatric HPD was relatively scant, research suggested similar familial dysfunction (e.g., limited independence, low family cohesion, family violence). Collectively, only 1 article, examining BDD, assessed family functioning within other OCRDs. This review supports the need for further research in the OCRDs. Limitations to the available literature and targeted suggestions for future research are discussed. The domains of family environment in this study indicate specific family functioning deficits that may serve as aetiological and/or maintenance factors in paediatric OCRDs, possibly contributing to the understanding of these complex disorders. The recognition of family deficits

  17. Permeability of cork to gases.

    Science.gov (United States)

    Faria, David P; Fonseca, Ana L; Pereira, Helen; Teodoro, Orlando M N D

    2011-04-27

    The permeability of gases through uncompressed cork was investigated. More than 100 samples were assessed from different plank qualities to provide a picture of the permeability distribution. A novel technique based on a mass spectrometer leak detector was used to directly measure the helium flow through the central area of small disks 10 mm in diameter and 2 mm thick. The permeability for nitrogen, oxygen, and other gases was measured by the pressure rise technique. Boiled and nonboiled cork samples from different sections were evaluated. An asymmetric frequency distribution ranging 3 orders of magnitude (roughly from 1 to 1000 μmol/(cm·atm·day)) for selected samples without macroscopic defects was found, having a peak below 100 μmol/(cm·atm·day). Correlation was found between density and permeability: higher density samples tend to show lower permeability. However, boiled cork showed a mean lower permeability despite having a lower density. The transport mechanism of gases through cork was also examined. Calculations suggest that gases permeate uncompressed cork mainly through small channels between cells under a molecular flow regime. The diameter of such channels was estimated to be in the range of 100 nm, in agreement with the plasmodesmata size in the cork cell walls.

  18. Task-related signal decrease on functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Hara, Yoshie; Nakamura, Mitsugu; Tamaki, Norihiko; Tamura, Shogo; Kitamura, Junji

    2001-01-01

    An atypical pattern of signal change was identified on functional magnetic resonance (fMR) imaging in pathologic patients. Three normal volunteers and 34 patients with pathologic lesions near the primary motor cortex underwent fMR imaging with echo-planar imaging while performing a hand motor task. Signal intensities were evaluated with the z-score method, and the time course and changes of the signal intensity were calculated. Nine of the 34 patients with pathologic lesions displayed a significant task-related signal reduction in motor-related areas. They also presented a conventional task-related signal increase in other motor-related areas. The time courses of the increase and decrease were the inverse of each other. There was no significant difference between rates of signal increase and decrease. Our findings suggest that this atypical signal decrease is clinically significant, and that impaired vascular reactivity and altered oxygen metabolism could contribute to the task-related signal reduction. Brain areas showing such task-related signal decrease should be preserved at surgery. (author)

  19. Effect of confining pressure on permeability behavior of Beishan granite

    International Nuclear Information System (INIS)

    Ma Like; Li Yunfeng; Zhao Xingguang; Tan Guohuan

    2012-01-01

    By using of the Electro-Hydraulic Servo-controlled Rock Mechanics Testing System (MTS 815.04) in the University of Hong Kong, a series of permeability tests were performed on specimens of Beishan granite at different confining pressures. The result indicates that: (1) there is a decrease of permeability due to progressive closure of initial microcracks and the corresponding volumetric strain is compressive when the confining pressures increase from 2.5 MPa to 15 MPa, (2) when the confining pressures decrease from 15 MPa to 2.5 MPa, there is an increase of permeability in this stage in relation with the volumetric dilation. (authors)

  20. Relating neuronal firing patterns to functional differentiation of cerebral cortex.

    Directory of Open Access Journals (Sweden)

    Shigeru Shinomoto

    2009-07-01

    Full Text Available It has been empirically established that the cerebral cortical areas defined by Brodmann one hundred years ago solely on the basis of cellular organization are closely correlated to their function, such as sensation, association, and motion. Cytoarchitectonically distinct cortical areas have different densities and types of neurons. Thus, signaling patterns may also vary among cytoarchitectonically unique cortical areas. To examine how neuronal signaling patterns are related to innate cortical functions, we detected intrinsic features of cortical firing by devising a metric that efficiently isolates non-Poisson irregular characteristics, independent of spike rate fluctuations that are caused extrinsically by ever-changing behavioral conditions. Using the new metric, we analyzed spike trains from over 1,000 neurons in 15 cortical areas sampled by eight independent neurophysiological laboratories. Analysis of firing-pattern dissimilarities across cortical areas revealed a gradient of firing regularity that corresponded closely to the functional category of the cortical area; neuronal spiking patterns are regular in motor areas, random in the visual areas, and bursty in the prefrontal area. Thus, signaling patterns may play an important role in function-specific cerebral cortical computation.

  1. Functional modules by relating protein interaction networks and gene expression.

    Science.gov (United States)

    Tornow, Sabine; Mewes, H W

    2003-11-01

    Genes and proteins are organized on the basis of their particular mutual relations or according to their interactions in cellular and genetic networks. These include metabolic or signaling pathways and protein interaction, regulatory or co-expression networks. Integrating the information from the different types of networks may lead to the notion of a functional network and functional modules. To find these modules, we propose a new technique which is based on collective, multi-body correlations in a genetic network. We calculated the correlation strength of a group of genes (e.g. in the co-expression network) which were identified as members of a module in a different network (e.g. in the protein interaction network) and estimated the probability that this correlation strength was found by chance. Groups of genes with a significant correlation strength in different networks have a high probability that they perform the same function. Here, we propose evaluating the multi-body correlations by applying the superparamagnetic approach. We compare our method to the presently applied mean Pearson correlations and show that our method is more sensitive in revealing functional relationships.

  2. [Advances in research on cognitive function related to temporal lobe epilepsy: focus on social cognitive function].

    Science.gov (United States)

    Yamano, Mitsuhiko; Akamatsu, Naoki; Tsuji, Sadatoshi

    2012-09-01

    Research on cognitive function related to temporal lobe epilepsy has thus far focused on memory, language, and general intelligence. Recently, however, the concept of social cognitive function has been proposed in the field of neuropsychology. Social cognitive function refers collectively to the higher cognitive functions that are essential in our social lives, and its representative aspects are facial expression recognition and decision-making. Emotional processing centered around the amygdala is thought to play a key role in the neural mechanism of this function. We conducted a study on the social cognitive function (decision-making) of patients with temporal lobe epilepsy, and found that this function is reduced in these patients, and that the right amygdalo-hippocampal complexes play an important role. In order to ensure the best possible treatment for epilepsy patients, it is necessary not only to make an accurate diagnosis and provide appropriate treatment, but also to provide support for enabling a smoother social life from the perspective of social cognitive function. Future research developments in this field are expected to contribute to total management in medical care for epilepsy patients.

  3. Relating zeta functions of discrete and quantum graphs

    Science.gov (United States)

    Harrison, Jonathan; Weyand, Tracy

    2018-02-01

    We write the spectral zeta function of the Laplace operator on an equilateral metric graph in terms of the spectral zeta function of the normalized Laplace operator on the corresponding discrete graph. To do this, we apply a relation between the spectrum of the Laplacian on a discrete graph and that of the Laplacian on an equilateral metric graph. As a by-product, we determine how the multiplicity of eigenvalues of the quantum graph, that are also in the spectrum of the graph with Dirichlet conditions at the vertices, depends on the graph geometry. Finally we apply the result to calculate the vacuum energy and spectral determinant of a complete bipartite graph and compare our results with those for a star graph, a graph in which all vertices are connected to a central vertex by a single edge.

  4. Mechanical and transport properties of rocks at high temperatures and pressures. Task II. Fracture permeability of crystalline rocks as a function of temperature, pressure, and hydrothermal alteration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, B.

    1985-11-01

    Pore-fluid chemical interactions on both short and long time scales can significantly change the permeability of a rock. Measurement of the permeability variations requires adaption and modification on standard measurement systems, with special attention given to pore-fluid flow rates and metal corrosion of system components. In this report, system requirements and capabilities are reviewed, analyzed, and recommendations made. Special attention is given to the choice of corrosion resistant metals, fluid-flow systems, back-pressure systems, jacketing materials, and flow-rate measurement. On the basis of this study, an economical, highly flexible, permeability system was designed and built. The system allows measurement of permeability over the darcy to nanodarcy range, using geologically meaningful, chemically reactive, pore fluids under constant volume flow rates as small as 0.2 ml/day at temperatures in excess of 300C, fluid pressures to 20 MPa, and confining pressures to 100 MPa. 7 refs., 3 figs., 1 tab.

  5. Fractal Theory for Permeability Prediction, Venezuelan and USA Wells

    Science.gov (United States)

    Aldana, Milagrosa; Altamiranda, Dignorah; Cabrera, Ana

    2014-05-01

    Inferring petrophysical parameters such as permeability, porosity, water saturation, capillary pressure, etc, from the analysis of well logs or other available core data has always been of critical importance in the oil industry. Permeability in particular, which is considered to be a complex parameter, has been inferred using both empirical and theoretical techniques. The main goal of this work is to predict permeability values on different wells using Fractal Theory, based on a method proposed by Pape et al. (1999). This approach uses the relationship between permeability and the geometric form of the pore space of the rock. This method is based on the modified equation of Kozeny-Carman and a fractal pattern, which allows determining permeability as a function of the cementation exponent, porosity and the fractal dimension. Data from wells located in Venezuela and the United States of America are analyzed. Employing data of porosity and permeability obtained from core samples, and applying the Fractal Theory method, we calculated the prediction equations for each well. At the beginning, this was achieved by training with 50% of the data available for each well. Afterwards, these equations were tested inferring over 100% of the data to analyze possible trends in their distribution. This procedure gave excellent results in all the wells in spite of their geographic distance, generating permeability models with the potential to accurately predict permeability logs in the remaining parts of the well for which there are no core samples, using even porority logs. Additionally, empirical models were used to determine permeability and the results were compared with those obtained by applying the fractal method. The results indicated that, although there are empirical equations that give a proper adjustment, the prediction results obtained using fractal theory give a better fit to the core reference data.

  6. The relation between attitudes toward functional foods and satisfaction with food-related life

    DEFF Research Database (Denmark)

    Schnettler, Berta; Adasme-Berríos, Cristian; Grunert, Klaus G

    2016-01-01

    Purpose The purpose of this paper is to assess the effect of attitudes towards functional foods (AFF) on university students’ satisfaction with food-related life (SWFL) and to distinguish student typologies, considering that the AFF are not homogeneous among consumers. Design/methodology/approach...

  7. Audibility of spectral differences in head-related transfer functions

    DEFF Research Database (Denmark)

    Hoffmann, Pablo F.F.; Møller, Henrik

    2006-01-01

    The spatial resolution at which head-related transfer functions (HRTFs) are available is an important aspect in the implementation of three-dimensional sound. Specifically, synthesis of moving sound requires that HRTFs are sufficiently close so the simulated sound is perceived as moving smoothly....... How close they must be, depends directly on how much the characteristics of neighboring HRTFs differ, and, most important, when these differences become audible. Differences between HRTFs exist in the interaural delay (ITD) and in the spectral characteristics, i.e. the magnitude spectrum of the HRTFs...

  8. Overvalue relative renal function in unilateral ureteropelvic junction obstruction?

    International Nuclear Information System (INIS)

    Baquedano, P.; Orellana, P.; Varas, J.

    2002-01-01

    Introduction: Relative renal function (RRF) is used as an important parameter in the surgical decision of hydronephrosis. In addition, the presence of a supranormal RRF (RRF > 55%) in the hydronephrotic kidney had been recognized. However, this over estimation is, in our experience, not only present with a RRF over 55%. We evaluated demographic data, ultrasonographic finding, age of surgery, presentation (antenatal diagnosis vs postnatal clinical symptoms) in children with unilateral hydronephrosis and a RRF which decreased after surgery. Materials and Methods: Of a series of 66 patients with unilateral ureteropyelic junction obstruction (UPJ) obstruction consecutively operated and followed in the Pediatric Urology unit of Catholic University of Chile, we analyzed 8 cases (12%) in which the relative renal function quantified by diuretic renography with Tc99 MAG3 decreased during follow-up after surgery, over 10% of the baseline value; 6 to 12 months post pyeloplasty, 7 boys, 6 cases with UPJ obstruction of the left side. 3 cases were diagnosed by prenatal ultrasound, 1 by abdominal mass, 1 by urinary tract infection, 1 by abdominal pain and 2 by screening. The age at the time of the surgery was in 4 cases 1 month of life, in two children between 6 and 12 months of age, one boy was 2.4 year old and another one was 7.3 year old. All were considered as a severe hydronefrosis in the ultrasound and 4 cases had a severe atrophy of renal parenchyma. The initial RRF of these cases varied from 35% to 62%. In half of the cases the initial RRF was considered normal, in 2 cases was abnormal ( 55%). In all of these children the RRF decreased after surgery in an average of 35% (28%-54%) of the initial RRF, none of these patients had a normal RRF after surgery. There was no differences in clinical presentation and radiological findings among them. However, it is worth to mention that the symptomatic presentation (pain, abdominal mass) was more frequent in this group that in our

  9. Are there approximate relations among transverse momentum dependent distribution functions?

    Energy Technology Data Exchange (ETDEWEB)

    Harutyun AVAKIAN; Anatoli Efremov; Klaus Goeke; Andreas Metz; Peter Schweitzer; Tobias Teckentrup

    2007-10-11

    Certain {\\sl exact} relations among transverse momentum dependent parton distribution functions due to QCD equations of motion turn into {\\sl approximate} ones upon the neglect of pure twist-3 terms. On the basis of available data from HERMES we test the practical usefulness of one such ``Wandzura-Wilczek-type approximation'', namely of that connecting $h_{1L}^{\\perp(1)a}(x)$ to $h_L^a(x)$, and discuss how it can be further tested by future CLAS and COMPASS data.

  10. Permeability of WIPP Salt During Damage Evolution and Healing

    International Nuclear Information System (INIS)

    BODNER, SOL R.; CHAN, KWAI S.; MUNSON, DARRELL E.

    1999-01-01

    The presence of damage in the form of microcracks can increase the permeability of salt. In this paper, an analytical formulation of the permeability of damaged rock salt is presented for both initially intact and porous conditions. The analysis shows that permeability is related to the connected (i.e., gas accessible) volumetric strain and porosity according to two different power-laws, which may be summed to give the overall behavior of a porous salt with damage. This relationship was incorporated into a constitutive model, known as the Multimechanism Deformation Coupled Fracture (MDCF) model, which has been formulated to describe the inelastic flow behavior of rock salt due to coupled creep, damage, and healing. The extended model was used to calculate the permeability of rock salt from the Waste Isolation Pilot Plant (WIPP) site under conditions where damage evolved with stress over a time period. Permeability changes resulting from both damage development under deviatoric stresses and damage healing under hydrostatic pressures were considered. The calculated results were compared against experimental data from the literature, which indicated that permeability in damaged intact WIPP salt depends on the magnitude of the gas accessible volumetric strain and not on the total volumetric strain. Consequently, the permeability of WIPP salt is significantly affected by the kinetics of crack closure, but shows little dependence on the kinetics of crack removal by sintering

  11. Compression characteristics and permeability of saturated Gaomiaozi ca-bentonite

    International Nuclear Information System (INIS)

    Sun Wenjing; Sun De'an; Fang Lei

    2012-01-01

    The compression characteristics and permeability of compacted Gaomiaozi Ca-bentonite saturated by the water uptake tests are studied by conducting a series of one-dimension compression tests. The permeability coefficient can be calculated by the Terzaghi's one-dimensional consolidation theory after the consolidation coefficient is obtained by the square root of time method. It is found that the compression curves of compacted specimens saturated by the water uptake tests tend to be consistent in the relatively high stress range. The compression indexes show a linear decrease with increasing dry density and the swelling index is a constant. The permeability coefficient decreases with increasing compression stress, and they show the linear relationship in double logarithmic coordinates. Meanwhile, the permeability coefficient shows a linear decrease with decreasing void ratio, which has no relationship with initial states, stress states and stress paths. The permeability coefficient k of GMZ Ca-bentonite at dry density Pd of 1.75 g/cm 3 can be calculated as 2.0 × 10 -11 cm/s by the linear relationship between Pd and log k. It is closed to the permeability coefficient of GMZ Ca-bentonite with the same dry density published in literature, which testifies that the method calculating the permeability coefficient is feasible from the consolidation coefficient obtained by the consolidation test. (authors)

  12. Characterization and estimation of permeability correlation structure from performance data

    Energy Technology Data Exchange (ETDEWEB)

    Ershaghi, I.; Al-Qahtani, M. [Univ. of Southern California, Los Angeles, CA (United States)

    1997-08-01

    In this study, the influence of permeability structure and correlation length on the system effective permeability and recovery factors of 2-D cross-sectional reservoir models, under waterflood, is investigated. Reservoirs with identical statistical representation of permeability attributes are shown to exhibit different system effective permeability and production characteristics which can be expressed by a mean and variance. The mean and variance are shown to be significantly influenced by the correlation length. Detailed quantification of the influence of horizontal and vertical correlation lengths for different permeability distributions is presented. The effect of capillary pressure, P{sub c1} on the production characteristics and saturation profiles at different correlation lengths is also investigated. It is observed that neglecting P{sub c} causes considerable error at large horizontal and short vertical correlation lengths. The effect of using constant as opposed to variable relative permeability attributes is also investigated at different correlation lengths. Next we studied the influence of correlation anisotropy in 2-D reservoir models. For a reservoir under five-spot waterflood pattern, it is shown that the ratios of breakthrough times and recovery factors of the wells in each direction of correlation are greatly influenced by the degree of anisotropy. In fully developed fields, performance data can aid in the recognition of reservoir anisotropy. Finally, a procedure for estimating the spatial correlation length from performance data is presented. Both the production performance data and the system`s effective permeability are required in estimating the correlation length.

  13. On the Huygens principle for bianisotropic mediums with symmetric permittivity and permeability dyadics

    Energy Technology Data Exchange (ETDEWEB)

    Faryad, Muhammad, E-mail: muhammad.faryad@lums.edu.pk [Department of Physics, Lahore University of Management Sciences, Lahore 54792 (Pakistan); Lakhtakia, Akhlesh [Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2017-02-19

    Mathematical statements of the Huygens principle relate the electric and magnetic field phasors at an arbitrary location in a source-free region enclosed by a surface to the tangential components of the electric and magnetic field phasors over that surface, via the dyadic Green functions applicable to the linear homogeneous medium occupying that region. We have mathematically formulated the Huygens principle for the electric and magnetic field phasors when the permittivity and permeability dyadics of the medium are symmetric, the symmetric parts of the two magnetoelectric dyadics of the medium are negative of each other, and both magnetoelectric dyadics also contain anti-symmetric terms. We have also formulated the Huygens principle for the electric (resp. magnetic) field phasor in a medium whose permittivity (resp. permeability) is scalar, the permeability (resp. permittivity) is symmetric, the symmetric parts of the two magnetoelectric dyadics reduce to dissimilar scalars, and anti-symmetric parts of the two magnetoelectric dyadics are identical. - Highlights: • The Huygens principle was formulated for bianistropic mediums when the permittivity and permeability dyadics of the medium are symmetric. • The formulation covers isotropic, biisotropic, and gyrotropic-like uniaxial mediums for which the Huygens principle is already available. • The formulation also covers new mediums like biaxial, chiro-omega, pseudo chiral, gyrotropic-like biaxial, and Lorentz reciprocal mediums.

  14. Modeling studies of unsaturated flow with long-term permeability change at Yucca Mountain

    International Nuclear Information System (INIS)

    Zhang Chengyuan; Liu Xiaoyan; Liu Quansheng

    2008-01-01

    The amount of water seeping into the waste emplacement drifts is crucial for the performance of underground nuclear waste repository, since it controls the corrosion rates of waste packages and the mobilization rate of radionuclides. It is limited by water flow through drift vicinity. In the present work we study the potential rates of water flow around drifts as a function of predicted long-term change of permeability at Yucca Mountain, based on a dual-continuum model of the unsaturated flow in fractured rock mass. For stage of DECOVALEX Ⅳ, we used a simplified practical model on unsaturated flow in Yucca Mountain case simulation. These models contain main physical processes that should be considered, including thermal expansion, thermal radiation, water-rock coupling and stress-induced change of permeability. Comparative study with other DECOVALEX team's results shows that they are both good enough and flexible enough to include more physical processes. We can draw the conclusion that it is necessary to model stress-induced changes in permeability and relative processes in future studies, because there are obvious differences (in water saturation and water flux) between simulation cases with and without variable permeability, especially in areas very close to the drift. (authors)

  15. Structural and Functional Changes in the Tight Junctions of Asymptomatic and Serology-negative First-degree Relatives of Patients With Celiac Disease.

    Science.gov (United States)

    Mishra, Asha; Prakash, Shyam; Sreenivas, Vishnubhatla; Das, Taposh K; Ahuja, Vineet; Gupta, Siddhartha D; Makharia, Govind K

    2016-08-01

    Ten to 15% of first-degree relatives (FDRs) of celiac disease (CeD) patients develop CeD. Although intestinal barrier functions (intestinal permeability) are abnormal in the subset of serology-negative FDRs, what leads to the abnormal barrier function is not known. To study the ultrastructure and functions of tight junctions in serology-negative FDRs of CeD patients. The intestinal permeability was measured in 97 asymptomatic and anti-tissue transglutaminase antibody (anti-tTG Ab)-negative FDRs (using the lactulose mannitol ratio) and in 75 controls. The ultrastructure of tight junctions using transmission electron microscopy, and the expression of key tight junction proteins (claudin-2, claudin-3, occludin, JAM-A, and ZO-1) and zonulin using real-time PCR and immunohistochemistry were assessed in anti-tTG Ab-negative, HLA-DQ2/-DQ8-positive FDRs having normal villi and in disease controls. In addition, the serum zonulin level was measured in 172 anti-tTG Ab-negative FDRs and 198 controls. The intestinal permeability was significantly increased in FDRs than in controls. Ultrastructural abnormalities such as dilatation of the tight junction (P=0.004) and loss of the pentalaminar structure (P=0.001) were more common in FDRs than in disease controls. There was significant underexpression of tight junction proteins ZO-1 (P=0.040) and occludin (P=0.041) in FDRs. There was no significant difference in the serum zonulin level between FDRs and controls (P=0.154). Even asymptomatic, anti-tTG-Ab-negative FDRs with a normal villous histology have both ultrastructural and functional abnormalities in tight junctions. These findings are indirect evidence of the presence of tight junction abnormalities before the onset of the disease and may have therapeutic implications.

  16. Executive functions, parental punishment, and aggression: Direct and moderated relations.

    Science.gov (United States)

    Fatima, Shameem; Sharif, Imran

    2017-12-01

    The main focus of the current study was to assess whether executive functions (EFs) moderate the effect of parental punishment on adolescent aggression. The sample were 370 participants (53% girls, 47% boys) enrolled at secondary and higher secondary levels and ranged in age between 13-19 years (M = 15.5, SD = 1.3). Participants were assessed on a self-report measure of aggression and two punishment measures, in addition to a demographic sheet. Then, they were individually assessed on four tests taken from the Delis-Kaplan Executive Functions System (D-KEFS) namely Trial Making Test (TMT), Design Fluency Test (DFT), Color Word Interference Test (CWIT), and Card Sorting Test (CST) to assess cognitive flexibility, nonverbal fluency, inhibition, and problem-solving ability, respectively. Correlation coefficients indicated that all four executive functioning measures and the two punishment measures were significantly correlated with aggression. Moderation analysis indicated that all EFs moderated the relationship between physical punishment and aggression, and only inhibition and problem-solving ability, but not cognitive flexibility and nonverbal fluency, moderated the relations between symbolic punishment and aggression. The findings support the hypothesis that EFs are protective personal factors that promote healthy adolescent adjustment in the presence of challenging environmental factors.

  17. Ethics of professional relations to functionally handicapped users

    Directory of Open Access Journals (Sweden)

    Mateja Griljc

    1999-01-01

    Full Text Available The basic purpose of 1ibrarianship code is to form and build librarian personality who can make possible the same opportunity to acquiring knowledge for all users, irrespective of their different demands or special needs.When we discuss the importance of building librarian personality the demanding work with users we confront the problem of ethical treatment very often. Ethics advises only general rules which are rarely simple and they are frequently opposite to each other.The process of reacting between the librarian and the user - as with general information needs as with special functional needs - is also dependent on librarian's professional relation which is formed on important elements such as professional qualification,experiences, creativeness and ethics.We are also interested in question where is the border between ethical and non - ethical action in key situations when the 1ibrarian meets functionally handicapped user. Opportunities for non - ethical reaction of professional workers are much more possible if the library's premises and the furniture don't offer suitable conditions for adaptable communication with the handicapped.But on the other side the 1ibrarian has just because of the bad arhitectural conditions better occasion to introduce himself as one of the best ethically formed personalies compared with other professions. With adaptable communication, creative work and with professional relation in offering help to disabled people, the librarian can contribute to more quality service and even more - he/she becomes an example to other professions - also in ethical sense.

  18. Bentonite Permeability at Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Katherine A. Daniels

    2017-01-01

    Full Text Available Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeability.

  19. Theory and test research on permeability of coal and rock body influenced by mining

    Energy Technology Data Exchange (ETDEWEB)

    Qing-xin Qi; Hong-yan Li; You-gang Wang; Zhi-gang Deng; Hang Lan; Yong-wei Peng; Chun-rui Li [China Coal Research Institute, Beijing (China)

    2009-06-15

    Stress distribution rules and deformation and failure properties of coal and rock bodies influenced by mining were analyzed. Experimental research on permeability of coal and rock samples under different loading conditions was finished in the laboratory. In-situ measurement of coal permeability influenced by actual mining was done as well. Theory analysis show that permeability varied with damage development of coal and rock under stress, and the influence of fissure on permeability was greatest. Laboratory results show that under different loading conditions permeability was different and it varied with stress, which indicated that permeability was directly related to the loading process. In-situ tests showed that permeability is related to abutment stress to some degree. The above results may be referenced to gas prevention and drainage. 11 refs., 6 figs., 1 tab.

  20. Decomposing the permeability spectra of nanocrystalline finemet core

    Directory of Open Access Journals (Sweden)

    Lajos K. Varga

    2018-04-01

    Full Text Available In this paper we present a theoretical and experimental investigation on the magnetization contributions to permeability spectra of normal annealed Finemet core with round type hysteresis curve. Real and imaginary parts of the permeability were determined as a function of exciting magnetic field (HAC between 40 Hz -110 MHz using an Agilent 4294A type Precision Impedance Analyzer. The amplitude of the exciting field was below and around the coercive field of the sample. The spectra were decomposed using the Levenberg–Marquardt algorithm running under Origin 9 software in four contributions: i eddy current; ii Debye relaxation of magnetization rotation, iii Debye relaxation of damped domain wall motion and iv resonant type DW motion. For small exciting amplitudes the first two components dominate. The last two contributions connected to the DW appear for relative large HAC only, around the coercive force. All the contributions will be discussed in detail accentuating the role of eddy current that is not negligible even for the smallest applied exciting field.

  1. The secondary permeability of Italian clays. A review

    International Nuclear Information System (INIS)

    Gera, F.

    1998-01-01

    Over the years several studies have been performed in Italy on the permeability of various argillaceous formations for the purpose of assessing their potential utilization for the isolation of long-lived radioactive waste. An extensive survey was made of tunnels intersecting clay formations for the purpose of identifying water inflows and of interpreting them in relation to the nature of the water-bearing features present outside the lining. The main objective of the 'Faults in Clays' project was to improve the sensitivity and resolution of geophysical techniques for identifying and characterizing faults intersecting clay strata. The first obvious conclusion is that generalizations are not possible: argillaceous formations are characterized by extreme variability in respect to intrinsic properties, sedimentological and structural set-up, consolidation history and regional stress conditions. As a result of this complexity widely different permeability, for both gas and water, has been observed even in apparently similar materials. In addition, gas data indicate that flow, at a particular location, can vary also as a function of time. (R.P.)

  2. Decomposing the permeability spectra of nanocrystalline finemet core

    Science.gov (United States)

    Varga, Lajos K.; Kovac, Jozef

    2018-04-01

    In this paper we present a theoretical and experimental investigation on the magnetization contributions to permeability spectra of normal annealed Finemet core with round type hysteresis curve. Real and imaginary parts of the permeability were determined as a function of exciting magnetic field (HAC) between 40 Hz -110 MHz using an Agilent 4294A type Precision Impedance Analyzer. The amplitude of the exciting field was below and around the coercive field of the sample. The spectra were decomposed using the Levenberg-Marquardt algorithm running under Origin 9 software in four contributions: i) eddy current; ii) Debye relaxation of magnetization rotation, iii) Debye relaxation of damped domain wall motion and iv) resonant type DW motion. For small exciting amplitudes the first two components dominate. The last two contributions connected to the DW appear for relative large HAC only, around the coercive force. All the contributions will be discussed in detail accentuating the role of eddy current that is not negligible even for the smallest applied exciting field.

  3. Functionally relevant diversity of closely related Nitrospira in activated sludge.

    Science.gov (United States)

    Gruber-Dorninger, Christiane; Pester, Michael; Kitzinger, Katharina; Savio, Domenico F; Loy, Alexander; Rattei, Thomas; Wagner, Michael; Daims, Holger

    2015-03-01

    Nitrospira are chemolithoautotrophic nitrite-oxidizing bacteria that catalyze the second step of nitrification in most oxic habitats and are important for excess nitrogen removal from sewage in wastewater treatment plants (WWTPs). To date, little is known about their diversity and ecological niche partitioning within complex communities. In this study, the fine-scale community structure and function of Nitrospira was analyzed in two full-scale WWTPs as model ecosystems. In Nitrospira-specific 16S rRNA clone libraries retrieved from each plant, closely related phylogenetic clusters (16S rRNA identities between clusters ranged from 95.8% to 99.6%) within Nitrospira lineages I and II were found. Newly designed probes for fluorescence in situ hybridization (FISH) allowed the specific detection of several of these clusters, whose coexistence in the WWTPs was shown for prolonged periods of several years. In situ ecophysiological analyses based on FISH, relative abundance and spatial arrangement quantification, as well as microautoradiography revealed functional differences of these Nitrospira clusters regarding the preferred nitrite concentration, the utilization of formate as substrate and the spatial coaggregation with ammonia-oxidizing bacteria as symbiotic partners. Amplicon pyrosequencing of the nxrB gene, which encodes subunit beta of nitrite oxidoreductase of Nitrospira, revealed in one of the WWTPs as many as 121 species-level nxrB operational taxonomic units with highly uneven relative abundances in the amplicon library. These results show a previously unrecognized high diversity of Nitrospira in engineered systems, which is at least partially linked to niche differentiation and may have important implications for process stability.

  4. Determination of saturation functions and wettability for chalk based on measured fluid saturations

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, D.; Bech, N.; Moeller Nielsen, C.

    1998-08-01

    The end effect of displacement experiments on low permeable porous media is used for determination of relative permeability functions and capillary pressure functions. Saturation functions for a drainage process are determined from a primary drainage experiment. A reversal of the flooding direction creates an intrinsic imbibition process in the sample, which enables determination if imbibition saturation functions. The saturation functions are determined by a parameter estimation technique. Scanning effects are modelled by the method of Killough. Saturation profiles are determined by NMR. (au)

  5. Using soft computing techniques to predict corrected air permeability using Thomeer parameters, air porosity and grain density

    Science.gov (United States)

    Nooruddin, Hasan A.; Anifowose, Fatai; Abdulraheem, Abdulazeez

    2014-03-01

    Soft computing techniques are recently becoming very popular in the oil industry. A number of computational intelligence-based predictive methods have been widely applied in the industry with high prediction capabilities. Some of the popular methods include feed-forward neural networks, radial basis function network, generalized regression neural network, functional networks, support vector regression and adaptive network fuzzy inference system. A comparative study among most popular soft computing techniques is presented using a large dataset published in literature describing multimodal pore systems in the Arab D formation. The inputs to the models are air porosity, grain density, and Thomeer parameters obtained using mercury injection capillary pressure profiles. Corrected air permeability is the target variable. Applying developed permeability models in recent reservoir characterization workflow ensures consistency between micro and macro scale information represented mainly by Thomeer parameters and absolute permeability. The dataset was divided into two parts with 80% of data used for training and 20% for testing. The target permeability variable was transformed to the logarithmic scale as a pre-processing step and to show better correlations with the input variables. Statistical and graphical analysis of the results including permeability cross-plots and detailed error measures were created. In general, the comparative study showed very close results among the developed models. The feed-forward neural network permeability model showed the lowest average relative error, average absolute relative error, standard deviations of error and root means squares making it the best model for such problems. Adaptive network fuzzy inference system also showed very good results.

  6. Investigation of the functional lifetime of TRISOPLASTr in relation to chemical compositions of pore water solutions in barriers

    NARCIS (Netherlands)

    Boels, D.; Beest, te H.; Zweers, H.; Groeneveld, P.

    2003-01-01

    Trisoplastr is a mixture of sand, bentonite and a polymer, used amongst others as landfill cover as well as barriers. Its permeability is generally lower than 1-2 x 10-11 m/s. Trisoplast keeps its functionality even in contact with different kinds of liquids, is not susceptible to cyclic drying and

  7. Minoxidil may suppress androgen receptor-related functions.

    Science.gov (United States)

    Hsu, Cheng-Lung; Liu, Jai-Shin; Lin, An-Chi; Yang, Chih-Hsun; Chung, Wen-Hung; Wu, Wen-Guey

    2014-04-30

    Although minoxidil has been used for more than two decades to treat androgenetic alopecia (AGA), an androgen-androgen receptor (AR) pathway-dominant disease, its precise mechanism of action remains elusive. We hypothesized that minoxidil may influence the AR or its downstream signaling. These tests revealed that minoxidil suppressed AR-related functions, decreasing AR transcriptional activity in reporter assays, reducing expression of AR targets at the protein level, and suppressing AR-positive LNCaP cell growth. Dissecting the underlying mechanisms, we found that minoxidil interfered with AR-peptide, AR-coregulator, and AR N/C-terminal interactions, as well as AR protein stability. Furthermore, a crystallographic analysis using the AR ligand-binding domain (LBD) revealed direct binding of minoxidil to the AR in a minoxidil-AR-LBD co-crystal model, and surface plasmon resonance assays demonstrated that minoxidil directly bound the AR with a K(d) value of 2.6 µM. Minoxidil also suppressed AR-responsive reporter activity and decreased AR protein stability in human hair dermal papilla cells. The current findings provide evidence that minoxidil could be used to treat both cancer and age-related disease, and open a new avenue for applications of minoxidil in treating androgen-AR pathway-related diseases.

  8. Permeability enhancement by shock cooling

    Science.gov (United States)

    Griffiths, Luke; Heap, Michael; Reuschlé, Thierry; Baud, Patrick; Schmittbuhl, Jean

    2015-04-01

    The permeability of an efficient reservoir, e.g. a geothermal reservoir, should be sufficient to permit the circulation of fluids. Generally speaking, permeability decreases over the life cycle of the geothermal system. As a result, is usually necessary to artificially maintain and enhance the natural permeability of these systems. One of the methods of enhancement -- studied here -- is thermal stimulation (injecting cold water at low pressure). This goal of this method is to encourage new thermal cracks within the reservoir host rocks, thereby increasing reservoir permeability. To investigate the development of thermal microcracking in the laboratory we selected two granites: a fine-grained (Garibaldi Grey granite, grain size = 0.5 mm) and a course-grained granite (Lanhelin granite, grain size = 2 mm). Both granites have an initial porosity of about 1%. Our samples were heated to a range of temperatures (100-1000 °C) and were either cooled slowly (1 °C/min) or shock cooled (100 °C/s). A systematic microstructural (2D crack area density, using standard stereological techniques, and 3D BET specific surface area measurements) and rock physical property (porosity, P-wave velocity, uniaxial compressive strength, and permeability) analysis was undertaken to understand the influence of slow and shock cooling on our reservoir granites. Microstructurally, we observe that the 2D crack surface area per unit volume and the specific surface area increase as a result of thermal stressing, and, for the same maximum temperature, crack surface area is higher in the shock cooled samples. This observation is echoed by our rock physical property measurements: we see greater changes for the shock cooled samples. We can conclude that shock cooling is an extremely efficient method of generating thermal microcracks and modifying rock physical properties. Our study highlights that thermal treatments are likely to be an efficient method for the "matrix" permeability enhancement of

  9. Stereotype threat and executive functions: which functions mediate different threat-related outcomes?

    Science.gov (United States)

    Rydell, Robert J; Van Loo, Katie J; Boucher, Kathryn L

    2014-03-01

    Stereotype threat research shows that women's math performance can be reduced by activating gender-based math stereotypes. Models of stereotype threat assert that threat reduces cognitive functioning, thereby accounting for its negative effects. This work provides a more detailed understanding of the cognitive processes through which stereotype threat leads women to underperform at math and to take risks, by examining which basic executive functions (inhibition, shifting, and updating) account for these outcomes. In Experiments 1 and 2, women under threat showed reduced inhibition, reduced updating, and reduced math performance compared with women in a control condition (or men); however, only updating accounted for women's poor math performance under threat. In Experiment 3, only updating accounted for stereotype threat's effect on women's math performance, whereas only inhibition accounted for the effect of threat on risk-taking, suggesting that distinct executive functions can account for different stereotype threat-related outcomes.

  10. The Functional Classification of Brain Damage-Related Vision Loss

    Science.gov (United States)

    Colenbrander, August

    2009-01-01

    This article provides a terminological framework to show the relationships among different types of visual deficits. It distinguishes between visual functions, which describe how the eye and the lower visual system function, and functional vision, which describes how a person functions. When visual functions are disturbed, the term "visual…

  11. Neuropsychological functioning related to specific characteristics of nocturnal enuresis.

    Science.gov (United States)

    Van Herzeele, C; Dhondt, K; Roels, S P; Raes, A; Groen, L-A; Hoebeke, P; Walle, J Vande

    2015-08-01

    for NP of a urine output exceeding 100% of the EBC is more in line with the recent findings of the Aarhus group. For children with MNE and associated NP, a high comorbidity with the predominantly inattentive presentation of ADHD was demonstrated. Children experienced problems with daytime functioning in relation to their wetting problem at night. According to the teachers, a low maximum voided volume was associated with more attention problems, and a high number of nights with NP was associated with more behaviour-regulation problems. Although comorbidity is still the appropriate word to use, the observation favours a more complex pathogenesis of enuresis with a common pathway in the central nervous system, including: neurotransmitters, influencing neuropsychological functioning as well as sleep, circadian rhythm of diuresis and bladder function control. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  12. Assessing Differential Item Functioning on the Test of Relational Reasoning

    Directory of Open Access Journals (Sweden)

    Denis Dumas

    2018-03-01

    Full Text Available The test of relational reasoning (TORR is designed to assess the ability to identify complex patterns within visuospatial stimuli. The TORR is designed for use in school and university settings, and therefore, its measurement invariance across diverse groups is critical. In this investigation, a large sample, representative of a major university on key demographic variables, was collected, and the resulting data were analyzed using a multi-group, multidimensional item-response theory model-comparison procedure. No significant differential item functioning was found on any of the TORR items across any of the demographic groups of interest. This finding is interpreted as evidence of the cultural fairness of the TORR, and potential test-development choices that may have contributed to that cultural fairness are discussed.

  13. Can we use IEC 61850 for safety related functions?

    Directory of Open Access Journals (Sweden)

    Luca Rocca

    2016-08-01

    Full Text Available Safety is an essential issue for processes that present high risk for human beings and environment. An acceptable level of risk is obtained both with actions on the process itself (risk reduction and with the use of special safety systems that switch the process into safe mode when a fault or an abnormal operation mode happens. These safety systems are today based on digital devices that communicate through digital networks. The IEC 61508 series specifies the safety requirements of all the devices that are involved in a safety function, including the communication network. Also electrical generation and distribution systems are processes that may have a significant level of risk, so the criteria stated by the IEC 61508 applies. Starting from this consideration, the paper analyzes the safety requirement for the communication network and compare them with the services of the communication protocol IEC 61850 that represents the most used protocol for automation of electrical plants. The goal of this job is to demonstrate that, from the technical point of view, IEC 61850 can be used for implementing safety-related functions, even if a formal safety certification is still missing.

  14. Revisiting 'Respiratory Function in Emphysema in Relation to Prognosis'

    Directory of Open Access Journals (Sweden)

    David V Bates

    2000-01-01

    Full Text Available BACKGROUND: The 1956 paper by DV Bates, JMS Knott and RV Christie, "Respiratory function in emphysema in relation to prognosis" Quart J Med 1956;97:137-157 is largely reprinted with a commentary by the first author, Dr David Bates. Although the pathology of emphysema was well recognized at the time, the clinical diagnosis and assessment of its severity were known to be imprecise; physiological measurements assessing and following the clinical course had not been established. The study aimed to follow systematically a group of patients, selected by clinical criteria using standardized clinical and physiological techniques, over four years and correlate physiological and clinical changes in relation to prognosis and eventually to postmortem findings. Fifty-nine patients were recruited to an emphysema clinic at St Bartholomew's Hospital, London, England. Inclusion criteria were dyspnea without other causes and no cor pulmonale present. Patients' symptoms were assessed by a standardized questionnaire, and measurements were taken of lung volumes, maximal ventilatory volume, carbon monoxide diffusing capacity at rest, exercise and oxygen saturation by oximetry.  During the four years of the study, 17 patients died (actuarial expected - four and 13 presented with signs of pulmonary heart failure. All postmortem examinations (n=9 showed advanced emphysema. A seasonal variation in dyspnea was established (the period included the infamous 1952 London smog. Four patients improved, and the remainder were unchanged or deteriorated. Close relationships were shown between dyspnea and function results, particularly for the diffusing capacity of lungs for carbon monoxide (DLCO. A comparison among a group of patients with chronic bronchitis without dyspnea showed that the DLCO discriminated between them. A loss of the normal increase in DLCO during exercise was shown in emphysema.

  15. Transverse Chemotactic Migration of Bacteria from High to Low Permeability Regions in a Dual Permeability Porous Microfluidic Device

    Science.gov (United States)

    Singh, R.; Olson, M. S.

    2011-12-01

    Low permeability regions sandwiched between high permeability regions such as clay lenses are difficult to treat using conventional treatment methods. Trace concentrations of contaminants such as non-aqueous phase liquids (NAPLs) remain trapped in these regions and over the time diffuse out into surrounding water thereby acting as a long term source of groundwater contamination. Bacterial chemotaxis (directed migration toward a contaminant source), may be helpful in enhancing bioremediation of such contaminated sites. This study is focused on simulating a two-dimensional dual-permeability groundwater contamination scenario using microfluidic devices and evaluating transverse chemotactic migration of bacteria from high to low permeability regions. A novel bi-layer polydimethylsiloxane (PDMS) microfluidic device was fabricated using photolithography and soft lithography techniques to simulate contamination of a dual- permeability region due to leakage from an underground storage tank into a low permeability region. This device consists of a porous channel through which a bacterial suspension (Escherchia Coli HCB33) is flown and another channel for injecting contaminant/chemo-attractant (DL-aspertic acid) into the porous channel. The pore arrangement in the porous channel contains a 2-D low permeability region surrounded by high permeability regions on both sides. Experiments were performed under chemotactic and non-chemotactic (replacing attractant with buffer solution in the non porous channel) conditions. Images were captured in transverse pore throats at cross-sections 4.9, 9.8, and 19.6 mm downstream from the attractant injection point and bacteria were enumerated in the middle of each pore throat. Bacterial chemotaxis was quantified in terms of the change in relative bacterial counts in each pore throat at cross-sections 9.8 and 19.6 mm with respect to counts at the cross-section at 4.9 mm. Under non-chemotactic conditions, relative bacterial count was observed

  16. Maladaptively high and low openness: the case for experiential permeability.

    Science.gov (United States)

    Piedmont, Ralph L; Sherman, Martin F; Sherman, Nancy C

    2012-12-01

    The domain of Openness within the Five-Factor Model (FFM) has received inconsistent support as a source for maladaptive personality functioning, at least when the latter is confined to the disorders of personality included within the American Psychiatric Association's (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR; APA, ). However, an advantage of the FFM relative to the DSM-IV-TR is that the former was developed to provide a reasonably comprehensive description of general personality structure. Rather than suggest that the FFM is inadequate because the DSM-IV-TR lacks much representation of Openness, it might be just as reasonable to suggest that the DSM-IV-TR is inadequate because it lacks an adequate representation of maladaptive variants of both high and low Openness. This article discusses the development and validation of a measure of these maladaptive variants, the Experiential Permeability Inventory. © 2012 The Authors. Journal of Personality © 2012, Wiley Periodicals, Inc.

  17. The permeability and consolidation of deep-sea sediments

    International Nuclear Information System (INIS)

    Schultheiss, P.J.; Gunn, D.E.

    1985-01-01

    This report presents permeability and consolidation data for a wide range of sediment types. Permeability is one of the two parameters which are needed to directly quantify pore water advection in deep sea sediments and which are being investigated in high-level radioactive waste study areas. While it is desirable that these parameters should be measured in situ it is argued that values of permeability can be measured sufficiently accurately in the laboratory from core samples. Consequently, an apparatus has been developed which enables sediment permeability to be measured at decreasing void ratios during a back-pressured consolidation test. Data presented in this report from over 60 samples have established the major differences in permeability between various sediment types and how permeability changes as a function of burial depth and void ratio. Samples from two study areas in the North Atlantic Ocean, King's Trough Flank (KTF) and Great Meteor East (GME), have been compared with samples of Red Clay (RC) obtained from the NW Pacific Ocean. Results are presented and discussed. (author)

  18. Modification of permeability of frog perineurium to [14C]-sucrose by stretch and hypertonicity

    International Nuclear Information System (INIS)

    Weerasuriya, A.; Rapoport, S.I.; Taylor, R.E.

    1979-01-01

    An in vitro method has been developed to determine quantitatively the permeability of the perineurium to radiotracers at room temperature. The permeability to [ 14 C]sucrose of the isolated perineurium of the sciatic nerve of the frog, Rana pipiens, was measured at rest length, when the perineurium was stretched and after the perineurium had been subjected to hypertonic treatment. Mean permeability at rest length was calculated to be 5.6 +- 0.27 (S.E.M., n=45)x10 -7 cm/sec, and both stretch and hypertonic treatment increased the permeability. A 10% stretch increased permeability reversibly, whereas a 20% stretch or immersion of the perineurium in a hypertonic bath increased permeability irreversibly. Altered permeability under these conditions might be related to changes in the ultrastructure of tight junctions in the perineurium. (Auth.)

  19. Highly permeable, cement-bounded backfilling mortars for SMA repositories

    International Nuclear Information System (INIS)

    Jacobs, F.; Mayer, G.; Wittmann, F.H.

    1994-03-01

    In low- and intermediate-level waste repositories, gas is produced due e.g. to corrosion. This gas must be able to escape from the repository in order to prevent damage to the repository structure. A cement-based backfill should take over this function. For this purpose, the composition of cement-based materials was varied to study their influence on porosity and permeability. In parallel to this study the behaviour of fresh concrete, the liberation of the heat of hydration and the hardened concrete properties were investigated. To characterize the permeability of cement-based materials the following parameters are important: 1) composition of the material (pore fabric), 2) storage conditions (degree of saturation), 3) degree of hydration (age), 4) measuring fluid. A change in the composition of cement-based materials can vary the permeability by ten orders of magnitude. It is shown that, by using dense aggregates, the transport of the fluid takes place through the matrix and along the aggregate/matrix interface. By using porous aggregates the permeability can be increased by two orders of magnitude. In the case of a dense matrix, porous aggregates do not alter the permeability. Increasing the matrix content or interface content increases permeability. Hence light weight mortars are an obvious choice. Like-grained mixes showed higher permeabilities in combination with better mechanical properties but, in comparison to normal mixes, they showed worse flow properties. With the composition cement-: water-: aggregate content 1:0.4:5.33 the likegrained mix with aggregates ranging from 2 to 3 mm proved to be a suitable material. With a low compaction after 28 days this mix reaches a permeability of 4.10 -12 m 2 and an uniaxial cylinder compressive strength of 16 N/mm 2 . (author) 58 figs., 23 tabs., refs

  20. Quantum Thermodynamics at Strong Coupling: Operator Thermodynamic Functions and Relations

    Directory of Open Access Journals (Sweden)

    Jen-Tsung Hsiang

    2018-05-01

    Full Text Available Identifying or constructing a fine-grained microscopic theory that will emerge under specific conditions to a known macroscopic theory is always a formidable challenge. Thermodynamics is perhaps one of the most powerful theories and best understood examples of emergence in physical sciences, which can be used for understanding the characteristics and mechanisms of emergent processes, both in terms of emergent structures and the emergent laws governing the effective or collective variables. Viewing quantum mechanics as an emergent theory requires a better understanding of all this. In this work we aim at a very modest goal, not quantum mechanics as thermodynamics, not yet, but the thermodynamics of quantum systems, or quantum thermodynamics. We will show why even with this minimal demand, there are many new issues which need be addressed and new rules formulated. The thermodynamics of small quantum many-body systems strongly coupled to a heat bath at low temperatures with non-Markovian behavior contains elements, such as quantum coherence, correlations, entanglement and fluctuations, that are not well recognized in traditional thermodynamics, built on large systems vanishingly weakly coupled to a non-dynamical reservoir. For quantum thermodynamics at strong coupling, one needs to reexamine the meaning of the thermodynamic functions, the viability of the thermodynamic relations and the validity of the thermodynamic laws anew. After a brief motivation, this paper starts with a short overview of the quantum formulation based on Gelin & Thoss and Seifert. We then provide a quantum formulation of Jarzynski’s two representations. We show how to construct the operator thermodynamic potentials, the expectation values of which provide the familiar thermodynamic variables. Constructing the operator thermodynamic functions and verifying or modifying their relations is a necessary first step in the establishment of a viable thermodynamics theory for

  1. Hippocampal sleep features: relations to human memory function

    Directory of Open Access Journals (Sweden)

    Michele eFerrara

    2012-04-01

    Full Text Available The recent spread of intracranial EEG recordings techniques for presurgical evaluation of drug-resistant epileptic patients is providing new information on the activity of different brain structures during both wakefulness and sleep. The interest has been mainly focused on the medial temporal lobe, and in particular the hippocampal formation, whose peculiar local sleep features have been recently described, providing support to the idea that sleep is not a spatially global phenomenon. The study of the hippocampal sleep electrophysiology is particularly interesting because of its central role in the declarative memory formation. Recent data indicate that sleep contributes to memory formation. Therefore, it is relevant to understand whether specific pattern of activity taking place during sleep are related to memory consolidation processes. Fascinating similarities between different states of consciousness (wakefulness, REM sleep, NREM sleep in some electrophysiological mechanisms underlying cognitive processes have been reported. For instance, large-scale synchrony in gamma activity is important for waking memory and perception processes, and its changes during sleep may be the neurophysiological substrate of sleep-related deficits of declarative memory. Hippocampal activity seems to specifically support memory consolidation during sleep, through specific coordinated neurophysiological events (slow waves, spindles, ripples that would facilitate the integration of new information into the pre-existing cortical networks. A few studies indeed provided direct evidence that rhinal ripples as well as slow hippocampal oscillations are correlated with memory consolidation in humans. More detailed electrophysiological investigations assessing the specific relations between different types of memory consolidation and hippocampal EEG features are in order. These studies will add an important piece of knowledge to the elucidation of the ultimate sleep

  2. Hippocampal Sleep Features: Relations to Human Memory Function

    Science.gov (United States)

    Ferrara, Michele; Moroni, Fabio; De Gennaro, Luigi; Nobili, Lino

    2012-01-01

    The recent spread of intracranial electroencephalographic (EEG) recording techniques for presurgical evaluation of drug-resistant epileptic patients is providing new information on the activity of different brain structures during both wakefulness and sleep. The interest has been mainly focused on the medial temporal lobe, and in particular the hippocampal formation, whose peculiar local sleep features have been recently described, providing support to the idea that sleep is not a spatially global phenomenon. The study of the hippocampal sleep electrophysiology is particularly interesting because of its central role in the declarative memory formation. Recent data indicate that sleep contributes to memory formation. Therefore, it is relevant to understand whether specific patterns of activity taking place during sleep are related to memory consolidation processes. Fascinating similarities between different states of consciousness (wakefulness, REM sleep, non-REM sleep) in some electrophysiological mechanisms underlying cognitive processes have been reported. For instance, large-scale synchrony in gamma activity is important for waking memory and perception processes, and its changes during sleep may be the neurophysiological substrate of sleep-related deficits of declarative memory. Hippocampal activity seems to specifically support memory consolidation during sleep, through specific coordinated neurophysiological events (slow waves, spindles, ripples) that would facilitate the integration of new information into the pre-existing cortical networks. A few studies indeed provided direct evidence that rhinal ripples as well as slow hippocampal oscillations are correlated with memory consolidation in humans. More detailed electrophysiological investigations assessing the specific relations between different types of memory consolidation and hippocampal EEG features are in order. These studies will add an important piece of knowledge to the elucidation of the ultimate

  3. The structure of executive functions and relations with early math learning

    NARCIS (Netherlands)

    van der Ven, S.H.G.

    2011-01-01

    In this dissertation, the relation between executive functions and mathematical skills in children was investigated. Two main aims were addressed: (1) unraveling the structure of executive functions, and (2) investigating the nature of the relations between executive functions and mathematics.

  4. EDZ and permeability in clayey rocks

    International Nuclear Information System (INIS)

    Levasseur, Severine; Collin, Frederic; Charlier, Robert; Besuelle, Pierre; Chambon, Rene; Viggiani, Cino

    2010-01-01

    Document available in extended abstract form only. Deep geological layers are being considered as potential host rocks for the high level radioactivity waste disposals. During drilling in host rocks, an excavated damaged zone - EDZ is created. The fluid transmissivity may be modified in this damaged zone. This paper deals with the permeability evolution in relation with diffuse and/or localized crack propagation in the material. We mainly focus on argillaceous rocks and on some underground laboratories: Mol URL in Boom clay, Bure URL in Callovo-Oxfordian clay and Mont-Terri URL in Opalinus clay. First, observations of damage around galleries are summarized. Structure of damage in localized zone or in fracture has been observed at underground gallery scale within the excavation damaged zone (EDZ). The first challenge for a correct understanding of all the processes occurring within the EDZ is the characterization at the laboratory scale of the damage and localization processes. The observation of the initiation and propagation of the localized zones needs for advanced techniques. X-ray tomography is a non-destructive imaging technique that allows quantification of internal features of an object in 3D. If mechanical loading of a specimen is applied inside a X-ray CT apparatus, successive 3D images at different loading steps show the evolution of the specimen. However, in general volumetric strain in a shear band is small compared to the shear strain and, unfortunately, in tomographic images grey level is mainly sensitive to the local mass density field. Such a limitation has been recently overcome by complementing X-ray tomography with 3D Volumetric Digital Image Correlation (V-DIC) which allows the determination of the full strain tensor field. Then it is possible to further explore the progression of localized deformation in the specimen. The second challenge is the robust modelling of the strain localized process. In fact, modelling the damage process with finite

  5. Functional Communication Profiles in Children with Cerebral Palsy in Relation to Gross Motor Function and Manual and Intellectual Ability.

    Science.gov (United States)

    Choi, Ja Young; Park, Jieun; Choi, Yoon Seong; Goh, Yu Ra; Park, Eun Sook

    2018-07-01

    The aim of the present study was to investigate communication function using classification systems and its association with other functional profiles, including gross motor function, manual ability, intellectual functioning, and brain magnetic resonance imaging (MRI) characteristics in children with cerebral palsy (CP). This study recruited 117 individuals with CP aged from 4 to 16 years. The Communication Function Classification System (CFCS), Viking Speech Scale (VSS), Speech Language Profile Groups (SLPG), Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS), and intellectual functioning were assessed in the children along with brain MRI categorization. Very strong relationships were noted among the VSS, CFCS, and SLPG, although these three communication systems provide complementary information, especially for children with mid-range communication impairment. These three communication classification systems were strongly related with the MACS, but moderately related with the GMFCS. Multiple logistic regression analysis indicated that manual ability and intellectual functioning were significantly related with VSS and CFCS function, whereas only intellectual functioning was significantly related with SLPG functioning in children with CP. Communication function in children with a periventricular white matter lesion (PVWL) varied widely. In the cases with a PVWL, poor functioning was more common on the SLPG, compared to the VSS and CFCS. Very strong relationships were noted among three communication classification systems that are closely related with intellectual ability. Compared to gross motor function, manual ability seemed more closely related with communication function in these children. © Copyright: Yonsei University College of Medicine 2018.

  6. miRNA-mediated functional changes through co-regulating function related genes.

    Directory of Open Access Journals (Sweden)

    Jie He

    Full Text Available BACKGROUND: MicroRNAs play important roles in various biological processes involving fairly complex mechanism. Analysis of genome-wide miRNA microarray demonstrate that a single miRNA can regulate hundreds of genes, but the regulative extent on most individual genes is surprisingly mild so that it is difficult to understand how a miRNA provokes detectable functional changes with such mild regulation. RESULTS: To explore the internal mechanism of miRNA-mediated regulation, we re-analyzed the data collected from genome-wide miRNA microarray with bioinformatics assay, and found that the transfection of miR-181b and miR-34a in Hela and HCT-116 tumor cells regulated large numbers of genes, among which, the genes related to cell growth and cell death demonstrated high Enrichment scores, suggesting that these miRNAs may be important in cell growth and cell death. MiR-181b induced changes in protein expression of most genes that were seemingly related to enhancing cell growth and decreasing cell death, while miR-34a mediated contrary changes of gene expression. Cell growth assays further confirmed this finding. In further study on miR-20b-mediated osteogenesis in hMSCs, miR-20b was found to enhance osteogenesis by activating BMPs/Runx2 signaling pathway in several stages by co-repressing of PPARγ, Bambi and Crim1. CONCLUSIONS: With its multi-target characteristics, miR-181b, miR-34a and miR-20b provoked detectable functional changes by co-regulating functionally-related gene groups or several genes in the same signaling pathway, and thus mild regulation from individual miRNA targeting genes could have contributed to an additive effect. This might also be one of the modes of miRNA-mediated gene regulation.

  7. Nitric oxide turnover in permeable river sediment

    DEFF Research Database (Denmark)

    Schreiber, Frank; Stief, Peter; Kuypers, Marcel M M

    2014-01-01

    We measured nitric oxide (NO) microprofiles in relation to oxygen (O2) and all major dissolved N-species (ammonium, nitrate, nitrite, and nitrous oxide [N2O]) in a permeable, freshwater sediment (River Weser, Germany). NO reaches peak concentrations of 0.13 μmol L-1 in the oxic zone and is consumed......-nitroso-N-acetylpenicillamine (SNAP) (1) confirmed denitrification as the main NO consumption pathway, with N2O as its major product, (2) showed that denitrification combines one free NO molecule with one NO molecule formed from nitrite to produce N2O, and (3) suggested that NO inhibits N2O reduction....

  8. Assessing the permeability of engineered capillary networks in a 3D culture.

    Directory of Open Access Journals (Sweden)

    Stephanie J Grainger

    Full Text Available Many pathologies are characterized by poor blood vessel growth and reduced nutrient delivery to the surrounding tissue, introducing a need for tissue engineered blood vessels. Our lab has developed a 3D co-culture method to grow interconnected networks of pericyte-invested capillaries, which can anastamose with host vasculature following implantation to restore blood flow to ischemic tissues. However, if the engineered vessels contain endothelial cells (ECs that are misaligned or contain wide junctional gaps, they may function improperly and behave more like the pathologic vessels that nourish tumors. The purpose of this study was to test the resistance to permeability of these networks in vitro, grown with different stromal cell types, as a metric of vessel functionality. A fluorescent dextran tracer was used to visualize transport across the endothelium and the pixel intensity was quantified using a customized MATLAB algorithm. In fibroblast-EC co-cultures, the dextran tracer easily penetrated through the vessel wall and permeability was high through the first 5 days of culture, indicative of vessel immaturity. Beyond day 5, dextran accumulated at the periphery of the vessel, with very little transported across the endothelium. Quantitatively, permeability dropped from initial levels of 61% to 39% after 7 days, and to 7% after 2 weeks. When ECs were co-cultured with bone marrow-derived mesenchymal stem cells (MSCs or adipose-derived stem cells (AdSCs, much tighter control of permeability was achieved. Relative to the EC-fibroblast co-cultures, permeabilities were reduced 41% for the EC-MSC co-cultures and 50% for the EC-AdSC co-cultures after 3 days of culture. By day 14, these permeabilities decreased by 68% and 77% over the EC-fibroblast cultures. Co-cultures containing stem cells exhibit elevated VE-cadherin levels and more prominent EC-EC junctional complexes when compared to cultures containing fibroblasts. These data suggest the stromal

  9. Saint Agatha Religious Festival in Catania: Stakeholders’ Functions and Relations

    Directory of Open Access Journals (Sweden)

    Salvatore Cannizzaro

    2017-03-01

    Full Text Available The purpose of the paper is to develop an explorative analysis of the functions and relations among actors involved in the organization and implementation of the Saint Agatha Religious Festival in Catania attracting nearly one million presences during the first week of February. The research is based on the survey of different sources of information, such as literature, news, media, and deep interviews with key informants pertaining to civil and religious institutions. The survey is designed to profile the Festival in terms of history, the character of the stakeholders, size, origin of assets, venues used, decision-making structure, and programs. The Festival’s use of volunteers and sponsors is specifically addressed. Empirical research sketches the network of stakeholders, the relationship between organizations, the importance of local social actors and strategies in enhancing local culture and sustainable tourism, regarding, in particular, the socio-cultural impacts of religious tourism. The local society has historical peculiarities which impose prudential considerations in generalizing about findings, and a comparative study with other Sicilian and/or Italian religious festivals will be important, mainly in order to delineate the actual sustainability of Festivals. The framework developed in this study can be helpful in the application of local social policies and also help comparative festival studies.

  10. Visual steady state in relation to age and cognitive function.

    Science.gov (United States)

    Horwitz, Anna; Dyhr Thomsen, Mia; Wiegand, Iris; Horwitz, Henrik; Klemp, Marc; Nikolic, Miki; Rask, Lene; Lauritzen, Martin; Benedek, Krisztina

    2017-01-01

    Neocortical gamma activity is crucial for sensory perception and cognition. This study examines the value of using non-task stimulation-induced EEG oscillations to predict cognitive status in a birth cohort of healthy Danish males (Metropolit) with varying cognitive ability. In particular, we examine the steady-state VEP power response (SSVEP-PR) in the alpha (8Hz) and gamma (36Hz) bands in 54 males (avg. age: 62.0 years) and compare these with 10 young healthy participants (avg. age 27.6 years). Furthermore, we correlate the individual alpha-to-gamma difference in relative visual-area power (ΔRV) with cognitive scores for the older adults. We find that ΔRV decrease with age by just over one standard deviation when comparing young with old participants (pintelligence is significantly negatively correlated with ΔRV in the older adult cohort, even when processing speed, global cognition, executive function, memory, and education (pincrease in ΔRV of one standard deviation is associated with a reduction in intelligence of 48% of a standard deviation (p<0.01). Finally, we conclude that the difference in cerebral rhythmic activity between the alpha and gamma bands is associated with age and cognitive status, and that ΔRV therefore provide a non-subjective clinical tool with which to examine cognitive status in old age.

  11. Visual steady state in relation to age and cognitive function.

    Directory of Open Access Journals (Sweden)

    Anna Horwitz

    Full Text Available Neocortical gamma activity is crucial for sensory perception and cognition. This study examines the value of using non-task stimulation-induced EEG oscillations to predict cognitive status in a birth cohort of healthy Danish males (Metropolit with varying cognitive ability. In particular, we examine the steady-state VEP power response (SSVEP-PR in the alpha (8Hz and gamma (36Hz bands in 54 males (avg. age: 62.0 years and compare these with 10 young healthy participants (avg. age 27.6 years. Furthermore, we correlate the individual alpha-to-gamma difference in relative visual-area power (ΔRV with cognitive scores for the older adults. We find that ΔRV decrease with age by just over one standard deviation when comparing young with old participants (p<0.01. Furthermore, intelligence is significantly negatively correlated with ΔRV in the older adult cohort, even when processing speed, global cognition, executive function, memory, and education (p<0.05. In our preferred specification, an increase in ΔRV of one standard deviation is associated with a reduction in intelligence of 48% of a standard deviation (p<0.01. Finally, we conclude that the difference in cerebral rhythmic activity between the alpha and gamma bands is associated with age and cognitive status, and that ΔRV therefore provide a non-subjective clinical tool with which to examine cognitive status in old age.

  12. Farm functionality changes in relation to changes in Agricultural policies

    DEFF Research Database (Denmark)

    Andersen, Peter Stubkjær; Vejre, Henrik; Dalgaard, Tommy

    2015-01-01

    function is strengthened, and the habitat and the recreation function are unchanged. This trend is also true for small, hobby farms whereas for big, full-time farms the production function is strengthened. In terms of multifunctionality the results suggest a general decrease in the balanced focus...

  13. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  14. Permeable Pavement Research - Edison, New Jersey

    Science.gov (United States)

    This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

  15. Quantifying porosity, compressibility and permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Frykman, Peter

    strain data. We found that Kozeny's modelled permeability fall in the same order of magnitude with measured permeability for shale rich in kaolinite but overestimates permeability by two to three orders of magnitudes for shale with high content of smectite. The empirical Yang and Aplin model gives good...... permeability estimate comparable to the measured one for shale rich in smectite. This is probably because Yang and Aplin model was calibrated in London clay which is rich in smectite....

  16. Age-Related Differences and Heterogeneity in Executive Functions: Analysis of NAB Executive Functions Module Scores.

    Science.gov (United States)

    Buczylowska, Dorota; Petermann, Franz

    2016-05-01

    Normative data from the German adaptation of the Neuropsychological Assessment Battery were used to examine age-related differences in 6 executive function tasks. A multivariate analysis of variance was employed to investigate the differences in performance in 484 participants aged 18-99 years. The coefficient of variation was calculated to compare the heterogeneity of scores between 10 age groups. Analyses showed an increase in the dispersion of scores with age, varying from 7% to 289%, in all subtests. Furthermore, age-dependent heterogeneity appeared to be associated with age-dependent decline because the subtests with the greatest increase in dispersion (i.e., Mazes, Planning, and Categories) also exhibited the greatest decrease in mean scores. In contrast, scores for the subtests Letter Fluency, Word Generation, and Judgment had the lowest increase in dispersion with the lowest decrease in mean scores. Consequently, the results presented here show a pattern of age-related differences in executive functioning that is consistent with the concept of crystallized and fluid intelligence. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Engineered Trehalose Permeable to Mammalian Cells.

    Directory of Open Access Journals (Sweden)

    Alireza Abazari

    Full Text Available Trehalose is a naturally occurring disaccharide which is associated with extraordinary stress-tolerance capacity in certain species of unicellular and multicellular organisms. In mammalian cells, presence of intra- and extracellular trehalose has been shown to confer improved tolerance against freezing and desiccation. Since mammalian cells do not synthesize nor import trehalose, the development of novel methods for efficient intracellular delivery of trehalose has been an ongoing investigation. Herein, we studied the membrane permeability of engineered lipophilic derivatives of trehalose. Trehalose conjugated with 6 acetyl groups (trehalose hexaacetate or 6-O-Ac-Tre demonstrated superior permeability in rat hepatocytes compared with regular trehalose, trehalose diacetate (2-O-Ac-Tre and trehalose tetraacetate (4-O-Ac-Tre. Once in the cell, intracellular esterases hydrolyzed the 6-O-Ac-Tre molecules, releasing free trehalose into the cytoplasm. The total concentration of intracellular trehalose (plus acetylated variants reached as high as 10 fold the extracellular concentration of 6-O-Ac-Tre, attaining concentrations suitable for applications in biopreservation. To describe this accumulation phenomenon, a diffusion-reaction model was proposed and the permeability and reaction kinetics of 6-O-Ac-Tre were determined by fitting to experimental data. Further studies suggested that the impact of the loading and the presence of intracellular trehalose on cellular viability and function were negligible. Engineering of trehalose chemical structure rather than manipulating the cell, is an innocuous, cell-friendly method for trehalose delivery, with demonstrated potential for trehalose loading in different types of cells and cell lines, and can facilitate the wide-spread application of trehalose as an intracellular protective agent in biopreservation studies.

  18. Cortactin deficiency is associated with reduced neutrophil recruitment but increased vascular permeability in vivo.

    Science.gov (United States)

    Schnoor, Michael; Lai, Frank P L; Zarbock, Alexander; Kläver, Ruth; Polaschegg, Christian; Schulte, Dörte; Weich, Herbert A; Oelkers, J Margit; Rottner, Klemens; Vestweber, Dietmar

    2011-08-01

    Neutrophil extravasation and the regulation of vascular permeability require dynamic actin rearrangements in the endothelium. In this study, we analyzed in vivo whether these processes require the function of the actin nucleation-promoting factor cortactin. Basal vascular permeability for high molecular weight substances was enhanced in cortactin-deficient mice. Despite this leakiness, neutrophil extravasation in the tumor necrosis factor-stimulated cremaster was inhibited by the loss of cortactin. The permeability defect was caused by reduced levels of activated Rap1 (Ras-related protein 1) in endothelial cells and could be rescued by activating Rap1 via the guanosine triphosphatase (GTPase) exchange factor EPAC (exchange protein directly activated by cAMP). The defect in neutrophil extravasation was caused by enhanced rolling velocity and reduced adhesion in postcapillary venules. Impaired rolling interactions were linked to contributions of β(2)-integrin ligands, and firm adhesion was compromised by reduced ICAM-1 (intercellular adhesion molecule 1) clustering around neutrophils. A signaling process known to be critical for the formation of ICAM-1-enriched contact areas and for transendothelial migration, the ICAM-1-mediated activation of the GTPase RhoG was blocked in cortactin-deficient endothelial cells. Our results represent the first physiological evidence that cortactin is crucial for orchestrating the molecular events leading to proper endothelial barrier function and leukocyte recruitment in vivo.

  19. Is trabecular bone permeability governed by molecular ordering-induced fluid viscosity gain? Arguments from re-evaluation of experimental data in the framework of homogenization theory.

    Science.gov (United States)

    Abdalrahman, T; Scheiner, S; Hellmich, C

    2015-01-21

    It is generally agreed on that trabecular bone permeability, a physiologically important quantity, is governed by the material׳s (vascular or intertrabecular) porosity as well as by the viscosity of the pore-filling fluids. Still, there is less agreement on how these two key factors govern bone permeability. In order to shed more light onto this somewhat open issue, we here develop a random homogenization scheme for upscaling Poiseuille flow in the vascular porosity, up to Darcy-type permeability of the overall porous medium "trabecular bone". The underlying representative volume element of the macroscopic bone material contains two types of phases: a spherical, impermeable extracellular bone matrix phase interacts with interpenetrating cylindrical pore channel phases that are oriented in all different space directions. This type of interaction is modeled by means of a self-consistent homogenization scheme. While the permeability of the bone matrix equals to zero, the permeability of the pore phase is found through expressing the classical Hagen-Poiseuille law for laminar flow in the format of a "micro-Darcy law". The upscaling scheme contains pore size and porosity as geometrical input variables; however, they can be related to each other, based on well-known relations between porosity and specific bone surface. As two key results, validated through comprehensive experimental data, it appears (i) that the famous Kozeny-Carman constant (which relates bone permeability to the cube of the porosity, the square of the specific surface, as well as to the bone fluid viscosity) needs to be replaced by an again porosity-dependent rational function, and (ii) that the overall bone permeability is strongly affected by the pore fluid viscosity, which, in case of polarized fluids, is strongly increased due to the presence of electrically charged pore walls. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Measuring the permeability of Eleana argillite from area 17, Nevada Test Site, using the transient method

    International Nuclear Information System (INIS)

    Lin, W.

    1978-01-01

    Using the transient method, we determine the permeability of high-quartz Eleana argillite from the Nevada Test Site as a function of effective pressure. By comparing calculated and observed pressure decay in the upstream reservoir, we have determined the permeability of intact and fractured specimens at effective pressures ranging from 1.0 to 24.0 MPa. Over this pressure range, Eleana argillite has a low permeability (10 -16 to 10 -19 cm 2 ) when intact and a higher permeability (10 -12 to 10 -17 cm 2 ) with one induced through-going fracture

  1. Functional genomics of beer-related physiological processes in yeast

    NARCIS (Netherlands)

    Hazelwood, L.A.

    2009-01-01

    Since the release of the entire genome sequence of the S. cerevisiae laboratory strain S288C in 1996, many functional genomics tools have been introduced in fundamental and application-oriented yeast research. In this thesis, the applicability of functional genomics for the improvement of yeast in

  2. Ileoanal pouch function is related to postprandial pouch tone

    NARCIS (Netherlands)

    Steens, J.; Bemelman, W. A.; Meijerink, W. J.; Griffioen, G.; van Hogezand, R. A.; Masclee, A. A.

    2001-01-01

    Functional impairments are frequently observed in patients with an ileoanal pouch. Meal ingestion increases pouch tone and motility. Little is known, however, about the influence of meal-stimulated pouch characteristics on pouch function. The aim was to characterize basal and postprandial pouch

  3. On some functional equations related to Steffensen's inequality

    Directory of Open Access Journals (Sweden)

    Bogdan Choczewski

    2004-05-01

    Full Text Available We consider the problem, proposed by the second author (cf. [1] of solving functional equations stemming from the Steffensen integral inequality (S, which is applicable in actuarial problems, cf. [4]. Imposing some regularity conditions we find solutions of two equations in two variables, one with two and another with three unknown functions.

  4. Fractals and spectra related to fourier analysis and function spaces

    CERN Document Server

    Triebel, Hans

    1997-01-01

    Fractals and Spectra Hans Triebel This book deals with the symbiotic relationship between the theory of function spaces, fractal geometry, and spectral theory of (fractal) pseudodifferential operators as it has emerged quite recently. Atomic and quarkonial (subatomic) decompositions in scalar and vector valued function spaces on the euclidean n-space pave the way to study properties (compact embeddings, entropy numbers) of function spaces on and of fractals. On this basis, distributions of eigenvalues of fractal (pseudo)differential operators are investigated. Diverse versions of fractal drums are played. The book is directed to mathematicians interested in functional analysis, the theory of function spaces, fractal geometry, partial and pseudodifferential operators, and, in particular, in how these domains are interrelated. ------ It is worth mentioning that there is virtually no literature on this topic and hence the most of the presented material is published here the first time. - Zentralblatt MATH (…) ...

  5. Permeability of protective coatings to tritium

    International Nuclear Information System (INIS)

    Braun, J.M.

    1987-10-01

    The permeability of four protective coatings to tritium gas and tritiated water was investigated. The coatings, including two epoxies, one vinyl and one urethane, were selected for their suitability in CANDU plant service in Ontario Hydro. Sorption rates of tritium gas into the coatings were considerably larger than for tritiated water, by as much as three to four orders of magnitude. However, as a result of the very large solubility of tritiated water in the coatings, the overall permeability to tritium gas and tritiated water are comparable, being somewhat larger for HTO. Marked differences were also evident among the four coatings, the vinyl proving to be unique in behaviour and morphology. Because of a highly porous surface structure water condensation takes place at high relative humidities, leading to an abnormally high retention of free water. Desorption rates from the four coatings were otherwise quite similar. Of practical importance was the observation that more effective desorption of tritiated water could be carried out at relatively high humidities, in this case 60%. It was believed that isotopic exchange was responsible for this phenomenon. It appears that epoxy coatings having a high pigment-to-binder ratio are most suited for coating concrete in tritium handling facilities

  6. Monitoring Strategies in Permeable Pavement Systems to Optimize Maintenance Scheduling

    Science.gov (United States)

    As the surface in a permeable pavement system clogs and performance decreases, maintenance is required to preserve the design function. Currently, guidance is limited for scheduling maintenance on an as needed basis. Previous research has shown that surface clogging in a permea...

  7. Effect of aggregate grain size distribution on properties of permeable ...

    African Journals Online (AJOL)

    ) ratio on the mechanical properties of permeable concrete is investigated. The aim of this study is to prepare permeable concrete mixture with optimum properties in terms of strength and permeability. For this purpose, five different permeable ...

  8. Permeability of hydrogen isotopes through Pd-Ag membrane

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi

    1981-01-01

    This paper represents the permeabilities, diffusion coefficients and isotope effects for hydrogen and deuterium through Pd-25 wt.% Ag alloy tubes The feed gas H 2 or D 2 flowing into the permeation cell was preheated before it reached to the outer surface of the permeation tube made of palladium-silver alloy. Permeation time lag method could be successfully carried out with the present apparatus to measure both permeability and diffusion coefficient. The square-root pressure dependence for the permeation of hydrogen isotopes was observed. The observed systematic temperature dependence indicates that the approximation of the Arrhenius' relation was effective within this experimental conditions. Some tendency of permeation fluxes in relation to the reciprocal temperature, 1/T, was seen. The permeability ratio was larger than the square root of isotopic mass ratio, and it decreased with temperature rise. On the contrary, the diffusion coefficient ratio was much smaller than the square root of isotopic mass ratio. (Kato, T.)

  9. Maass waveforms arising from sigma and related indefinite theta functions

    OpenAIRE

    Zwegers, Sander

    2010-01-01

    In this paper we consider an example of a Maass waveform which was constructed by Cohen from a function $\\sigma$, studied by Andrews, Dyson and Hickerson, and it's companion $\\sigma^*$. We put this example in a more general framework.

  10. On relation between distribution functions in hard and soft processes

    International Nuclear Information System (INIS)

    Kisselev, A.V.; Petrov, V.A.

    1992-10-01

    It is shown that in the particle-exchange model the hadron-hadron scattering amplitude admits parton-like representation with the distribution functions coinciding with those extracted from deep inelastic processes. (author). 13 refs

  11. Relating Anaerobic Digestion Microbial Community and Process Function.

    Science.gov (United States)

    Venkiteshwaran, Kaushik; Bocher, Benjamin; Maki, James; Zitomer, Daniel

    2015-01-01

    Anaerobic digestion (AD) involves a consortium of microorganisms that convert substrates into biogas containing methane for renewable energy. The technology has suffered from the perception of being periodically unstable due to limited understanding of the relationship between microbial community structure and function. The emphasis of this review is to describe microbial communities in digesters and quantitative and qualitative relationships between community structure and digester function. Progress has been made in the past few decades to identify key microorganisms influencing AD. Yet, more work is required to realize robust, quantitative relationships between microbial community structure and functions such as methane production rate and resilience after perturbations. Other promising areas of research for improved AD may include methods to increase/control (1) hydrolysis rate, (2) direct interspecies electron transfer to methanogens, (3) community structure-function relationships of methanogens, (4) methanogenesis via acetate oxidation, and (5) bioaugmentation to study community-activity relationships or improve engineered bioprocesses.

  12. An integrated approach to permeability modeling using micro-models

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, A.H.; Leuangthong, O.; Deutsch, C.V. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Alberta Univ., Edmonton, AB (Canada)

    2008-10-15

    An important factor in predicting the performance of steam assisted gravity drainage (SAGD) well pairs is the spatial distribution of permeability. Complications that make the inference of a reliable porosity-permeability relationship impossible include the presence of short-scale variability in sand/shale sequences; preferential sampling of core data; and uncertainty in upscaling parameters. Micro-modelling is a simple and effective method for overcoming these complications. This paper proposed a micro-modeling approach to account for sampling bias, small laminated features with high permeability contrast, and uncertainty in upscaling parameters. The paper described the steps and challenges of micro-modeling and discussed the construction of binary mixture geo-blocks; flow simulation and upscaling; extended power law formalism (EPLF); and the application of micro-modeling and EPLF. An extended power-law formalism to account for changes in clean sand permeability as a function of macroscopic shale content was also proposed and tested against flow simulation results. There was close agreement between the model and simulation results. The proposed methodology was also applied to build the porosity-permeability relationship for laminated and brecciated facies of McMurray oil sands. Experimental data was in good agreement with the experimental data. 8 refs., 17 figs.

  13. Age-related functional brain changes in young children.

    Science.gov (United States)

    Long, Xiangyu; Benischek, Alina; Dewey, Deborah; Lebel, Catherine

    2017-07-15

    Brain function and structure change significantly during the toddler and preschool years. However, most studies focus on older or younger children, so the specific nature of these changes is unclear. In the present study, we analyzed 77 functional magnetic resonance imaging datasets from 44 children aged 2-6 years. We extracted measures of both local (amplitude of low frequency fluctuation and regional homogeneity) and global (eigenvector centrality mapping) activity and connectivity, and examined their relationships with age using robust linear correlation analysis and strict control for head motion. Brain areas within the default mode network and the frontoparietal network, such as the middle frontal gyrus, the inferior parietal lobule and the posterior cingulate cortex, showed increases in local and global functional features with age. Several brain areas such as the superior parietal lobule and superior temporal gyrus presented opposite development trajectories of local and global functional features, suggesting a shifting connectivity framework in early childhood. This development of functional connectivity in early childhood likely underlies major advances in cognitive abilities, including language and development of theory of mind. These findings provide important insight into the development patterns of brain function during the preschool years, and lay the foundation for future studies of altered brain development in young children with brain disorders or injury. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The permeability of concrete for reactor containment vessels

    International Nuclear Information System (INIS)

    Mills, R.H.

    1983-07-01

    Review of the literature pertaining to water, water vapour and gas transmission through concrete revealed conflicting views on the mechanisms involved and the influence of mix design parameters such as initial porosities and water/cement ratio. Consideration of the effects of ageing and of construction defects in field concrete were totally neglected in published work. Permeability data from three published papers were compared with permeability calculated according to Powers. The ratio of calculated to observed permeability varied from 40 x 10 -3 to 860 x 10 -3 for one group: from 0.17 x 10 3 to 8.6 x 10 3 in the second; and from 24 x 10 3 to 142 x 10 3 for the third. There were therefore wide discrepancies within each group of data and between groups. A bibliography was prepared and an exploratory experimental programme was mounted to determine the relative importance of key parameters such as cement type, porosity and water/cement ratio. Contrary to frequently cited references it was found that permeability of concrete was not significantly influenced by water/cement ratio when the starting porosity was constant. If water/cement ratio was held constant, however, the permeability was strongly influenced by starting porosity. It was also found that with constant water/cement ratio permeability increased with cement content. The value of fly ash and blast furnace slag in partial substitution for Portland cement is neglected in the literature but it is important since such substitutions alleviate alkali-silicate reactions. Permeability of concrete was significantly decreased by partial substitution of Portland cement with fly ash but there was no benefit in the use of blast furnace slag

  15. Functional Thinking Ways in Relation to Linear Function Tables of Elementary School Students

    Science.gov (United States)

    Tanisli, Dilek

    2011-01-01

    One of the basic components of algebraic thinking is functional thinking. Functional thinking involves focusing on the relationship between two (or more) varying quantities and such thinking facilitates the studies on both algebra and the notion of function. The development of functional thinking of students should start in the early grades and it…

  16. Functional clustering in hippocampal cultures: relating network structure and dynamics

    International Nuclear Information System (INIS)

    Feldt, S; Dzakpasu, R; Olariu, E; Żochowski, M; Wang, J X; Shtrahman, E

    2010-01-01

    In this work we investigate the relationship between gross anatomic structural network properties, neuronal dynamics and the resultant functional structure in dissociated rat hippocampal cultures. Specifically, we studied cultures as they developed under two conditions: the first supporting glial cell growth (high glial group), and the second one inhibiting it (low glial group). We then compared structural network properties and the spatio-temporal activity patterns of the neurons. Differences in dynamics between the two groups could be linked to the impact of the glial network on the neuronal network as the cultures developed. We also implemented a recently developed algorithm called the functional clustering algorithm (FCA) to obtain the resulting functional network structure. We show that this new algorithm is useful for capturing changes in functional network structure as the networks evolve over time. The FCA detects changes in functional structure that are consistent with expected dynamical differences due to the impact of the glial network. Cultures in the high glial group show an increase in global synchronization as the cultures age, while those in the low glial group remain locally synchronized. We additionally use the FCA to quantify the amount of synchronization present in the cultures and show that the total level of synchronization in the high glial group is stronger than in the low glial group. These results indicate an interdependence between the glial and neuronal networks present in dissociated cultures

  17. Trauma-Related Dissociation Is Linked With Maladaptive Personality Functioning

    Directory of Open Access Journals (Sweden)

    Antonella Granieri

    2018-05-01

    Full Text Available Background: Extensive research has demonstrated the positive associations among the exposure to traumatic experiences, the levels of dissociation, and the severity of psychiatric symptoms in adults. However, it has been hypothesized in clinical literature that an excessive activation of the dissociative processes following multiple traumatic experiences may jeopardize the psychological and behavioral functioning of the individuals, fostering higher levels of maladaptive personality functioning.Methods: The study involved 322 adult volunteers from Italy. Participants completed measures on traumatic experiences, dissociation, and maladaptive personality traits.Results: The number of traumatic experiences reported by participants were positively associated with dissociation scores and maladaptive personality scores. Mediation analyses showed that dissociation acted as a partial mediator in the relationship between traumatic experiences and overall maladaptive personality functioning. Regression curve analyses showed that the positive association between maladaptive personality functioning and dissociation was stronger among participants with higher exposure to traumatic experiences.Conclusion: Exposure to multiple traumatic experiences may increase the risk for an excessive activation of the dissociative processes, which in turn may generate severe impairments in multiple domains of personality functioning.

  18. Current and evolving approaches for improving the oral permeability of BCS Class III or analogous molecules.

    Science.gov (United States)

    Dave, Vivek S; Gupta, Deepak; Yu, Monica; Nguyen, Phuong; Varghese Gupta, Sheeba

    2017-02-01

    The Biopharmaceutics Classification System (BCS) classifies pharmaceutical compounds based on their aqueous solubility and intestinal permeability. The BCS Class III compounds are hydrophilic molecules (high aqueous solubility) with low permeability across the biological membranes. While these compounds are pharmacologically effective, poor absorption due to low permeability becomes the rate-limiting step in achieving adequate bioavailability. Several approaches have been explored and utilized for improving the permeability profiles of these compounds. The approaches include traditional methods such as prodrugs, permeation enhancers, ion-pairing, etc., as well as relatively modern approaches such as nanoencapsulation and nanosizing. The most recent approaches include a combination/hybridization of one or more traditional approaches to improve drug permeability. While some of these approaches have been extremely successful, i.e. drug products utilizing the approach have progressed through the USFDA approval for marketing; others require further investigation to be applicable. This article discusses the commonly studied approaches for improving the permeability of BCS Class III compounds.

  19. Algebraic Structures Related to the Combination of Belief Functions

    Czech Academy of Sciences Publication Activity Database

    Daniel, Milan

    2004-01-01

    Roč. 60, č. 2 (2004), s. 245-255 ISSN 1346-0862 R&D Projects: GA MŠk OC 274.001 Grant - others:COST(XE) Action 274 TARSKI Institutional research plan: CEZ:AV0Z1030915 Keywords : belief functions * Dempster-Shafer theory * combination of belief functions * Dempster's semigroup * uncertainty processing * decision making * expert systems Subject RIV: BA - General Mathematics http://www.jams.or.jp/ scm /contents/Vol-10-5/10-50.pdf

  20. Age-related features of renal function (on radiorenographic data)

    International Nuclear Information System (INIS)

    Korkushko, O.V.; Frajfel'd, V.Eh.; Belyj, A.A.

    1986-01-01

    Renal function of 91 healthy subjects aged 18-91 has been evaluated at radionuclide renography with the use of 131 I-Hippuran. Renal excretory function, effective renal plasma and blood flows were found to decrease annually by 0.09 ml/kg in ageing men and by 0.08 ml/kg in women. The use of new indices may be useful for evaluation of renal blood circulation, especially during hypo- or hypervolaemia is proposed. These are the index of renal circulation efficiency and the mean time of circulating blood volume transfer through renal blood vessels

  1. Scaling behavior of gas permeability measurements in volcanic tuffs

    International Nuclear Information System (INIS)

    Tidwell, V.C.

    1994-01-01

    One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property scaling is addressed. Property scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property scaling with the aim of developing and testing models that describe scaling behavior in a quantitative manner. Scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. The approach is to systematically isolate those factors believed to influence property scaling and investigate their relative contributions to overall scaling behavior. Two blocks of tuff, each exhibiting differing heterogeneity structure, have recently been examined. Results of the investigation show very different scaling behavior, as exhibited by changes in the distribution functions and variograms, for the two tuff samples. Even for the relatively narrow range of measurement scales employed significant changes in the distribution functions, variograms, and summary statistics occurred. Because such data descriptors will likely play an important role in calculating effective media properties, these results demonstrate both the need to understand and accurately model scaling behavior

  2. METHODOLOGY FOR CALCULATION OF HORIZONTAL WATER PERMEABILITY COEFFICIENT IN SOIL CAPILLARY BORDER

    Directory of Open Access Journals (Sweden)

    E. I. Michnevich

    2011-01-01

    Full Text Available The paper shows that for overall estimation of soil water permeability it is necessary to know a horizontal water permeability value of a soil capillary border in addition to coefficients of filtration and permeability. Relations allowing to determine soil permeability in the area of incomplete saturation, are given in the paper. For a fully developed capillary border some calculation formulae have been obtained in the form of algebraic polynomial versus soil grading (grain composition. These formulae allow to make more accurate calculations while designing and operating  reclamation works.

  3. Permeability of highly compacted bentonite

    International Nuclear Information System (INIS)

    Pusch, R.

    1980-12-01

    The object of the study was the water flow through the bentonite which is caused by hydraulic gradients. The study comprised laboratory tests and theoretical considerations. It was found that high bulk densities reduced the permeability to very low values. It was concluded that practically impervious conditions prevail when the gradients are low. Thus with a regional gradient of 10 -2 and a premeability of 10 -13 m/s the flow rate will not be higher than approximately 1 mm in 30 000 years. (G.B.)

  4. Structure-Function Relations in Physiology Education: Where's the Mechanism?

    Science.gov (United States)

    Lira, Matthew E.; Gardner, Stephanie M.

    2017-01-01

    Physiology demands systems thinking: reasoning within and between levels of biological organization and across different organ systems. Many physiological mechanisms explain how structures and their properties interact at one level of organization to produce emergent functions at a higher level of organization. Current physiology principles, such…

  5. Exploring the function of relative sentences in New Testament Greek

    African Journals Online (AJOL)

    2015-08-14

    Aug 14, 2015 ... (2) Providing background or additional information for a nominal ... In view of this, Comrie (1989:142) argues that a functional (semantic, cognitive) definition .... προβάτων ['beware of false prophets, the very ones who come.

  6. Plurisubharmonic and holomorphic functions relative to the plurifine topology

    DEFF Research Database (Denmark)

    El Kadiri, M.; Fuglede, Bent; Wiegerinck, J.

    2011-01-01

    topology and f∘h is finely subharmonic for all complex affine-linear maps h. As a consequence, the regularization in the plurifine topology of a pointwise supremum of such functions is weakly plurifinely plurisubharmonic, and it differs from the pointwise supremum at most on a pluripolar set. Weak...

  7. Gender-related differences in functional connectivity in multiple sclerosis

    NARCIS (Netherlands)

    Schoonheim, M.M.; Hulst, H.E.; Landi, D.; Ciccarelli, O.; Roosendaal, S.D.; Sanz-Arigita, E.J.; Vrenken, H.; Polman, C.H.; Stam, C.J.; Barkhof, F.; Geurts, J.J.G.

    2012-01-01

    Background: Gender effects are strong in multiple sclerosis (MS), with male patients showing a worse clinical outcome than female patients. Functional reorganization of neural activity may contribute to limit disability, and possible gender differences in this process may have important clinical

  8. Determination of hydrogen permeability in commercial and modified superalloys

    Science.gov (United States)

    Bhattacharyya, S.; Peterman, W.

    1983-01-01

    The results of hydrogen permeability measurements on several iron- and cobalt-base alloys as well as on two long-ranged ordered alloys over the range of 705 to 870 C (1300 to 1600 F) are summarized. The test alloys included wrought alloys N-155, IN 800, A-286, 19-9DL, and 19-9DL modifications with aluminum, niobium, and misch metal. In addition, XF-818, CRM-6D, SA-F11, and HS-31 were evaluated. Two wrought long-range ordered alloys, Ni3Al and (Fe,Ni)3(V,Al) were also evaluated. All tests were conducted at 20.7 MPa pressure in either pure and/or 1% CO2-doped H2 for test periods as long as 133 h. Detailed analyses were conducted to determine the relative permeability rankings of these alloys and the effect of doping, exit surface oxidation, specimen design variations, and test duration on permeability coefficient, and permeation activation energies were determined. The two long-range ordered alloys had the lowest permeability coefficients in pure H2 when compared with the eight commercial alloys and their modifications. With CO2 doping, significant decrease in permeability was observed in commercial alloys--no doped tests were conducted with the long-range ordered alloys.

  9. Modeling stress/strain-dependent permeability changes for deep geoenergy applications

    Science.gov (United States)

    Rinaldi, Antonio Pio; Rutqvist, Jonny

    2016-04-01

    Rock permeability is a key parameter in deep geoenergy systems. Stress and strain changes induced at depth by fluid injection or extraction may substantially alter the rock permeability in an irreversible way. With regard to the geoenergies, some applications require the permeability to be enhanced to improve productivity. The rock permeability is generally enhanced by shearing process of faults and fractures (e.g. hydroshearing for Enhanced and Deep Geothermal Systems), or the creation of new fractures (e.g. hydrofracturing for shale gas). However, such processes may, at the same time, produce seismicity that can be felt by the local population. Moreover, the increased permeability due to fault reactivation may pose at risk the sealing capacity of a storage site (e.g. carbon sequestration or nuclear waste disposal), providing then a preferential pathway for the stored fluids to escape at shallow depth. In this work we present a review of some recent applications aimed at understanding the coupling between stress (or strain) and permeability. Examples of geoenergy applications include both EGS and CO2 sequestration. To investigate both "wanted" and "unwanted" effects, THM simulations have been carried out with the TOUGH-FLAC simulator. Our studies include constitutive equations relating the permeability to mean effective stress, effective normal stress, volumetric strain, as well as accounting for permeability variation as related to fault/fracture reactivation. Results show that the geomechanical effects have a large role in changing the permeability, hence affecting fluids leakage, reservoir enhancement, as well as the induced seismicity.

  10. On criteria for algebraic independence of collections of functions satisfying algebraic difference relations

    Directory of Open Access Journals (Sweden)

    Hiroshi Ogawara

    2017-01-01

    Full Text Available This paper gives conditions for algebraic independence of a collection of functions satisfying a certain kind of algebraic difference relations. As applications, we show algebraic independence of two collections of special functions: (1 Vignéras' multiple gamma functions and derivatives of the gamma function, (2 the logarithmic function, \\(q\\-exponential functions and \\(q\\-polylogarithm functions. In a similar way, we give a generalization of Ostrowski's theorem.

  11. The effect of offset on fracture permeability of rocks from the Southern Andes Volcanic Zone, Chile

    Science.gov (United States)

    Pérez-Flores, P.; Wang, G.; Mitchell, T. M.; Meredith, P. G.; Nara, Y.; Sarkar, V.; Cembrano, J.

    2017-11-01

    The Southern Andes Volcanic Zone (SVZ) represents one of the largest undeveloped geothermal provinces in the world. Development of the geothermal potential requires a detailed understanding of fluid transport properties of its main lithologies. The permeability of SVZ rocks is altered by the presence of fracture damage zones produced by the Liquiñe-Ofqui Fault System (LOFS) and the Andean Transverse Faults (ATF). We have therefore measured the permeability of four representative lithologies from the volcanic basement in this area: crystalline tuff, andesitic dike, altered andesite and granodiorite. For comparative purposes, we have also measured the permeability of samples of Seljadalur basalt, an Icelandic rock with widely studied and reported hydraulic properties. Specifically, we present the results of a systematic study of the effect of fractures and fracture offsets on permeability as a function of increasing effective pressure. Baseline measurements on intact samples of SVZ rocks show that the granodiorite has a permeability (10-18 m2), two orders of magnitude higher than that of the volcanic rocks (10-20 m2). The presence of throughgoing mated macro-fractures increases permeability by between four and six orders of magnitude, with the highest permeability recorded for the crystalline tuff. Increasing fracture offset to produce unmated fractures results in large increases in permeability up to some characteristic value of offset, beyond which permeability changes only marginally. The increase in permeability with offset appears to depend on fracture roughness and aperture, and these are different for each lithology. Overall, fractured SVZ rocks with finite offsets record permeability values consistent with those commonly found in geothermal reservoirs (>10-16 m2), which potentially allow convective/advective flow to develop. Hence, our results demonstrate that the fracture damage zones developed within the SVZ produce permeable regions, especially within the

  12. Antibiotic Treatment Affects Intestinal Permeability and Gut Microbial Composition in Wistar Rats Dependent on Antibiotic Class.

    Directory of Open Access Journals (Sweden)

    Monica Vera-Lise Tulstrup

    Full Text Available Antibiotics are frequently administered orally to treat bacterial infections not necessarily related to the gastrointestinal system. This has adverse effects on the commensal gut microbial community, as it disrupts the intricate balance between specific bacterial groups within this ecosystem, potentially leading to dysbiosis. We hypothesized that modulation of community composition and function induced by antibiotics affects intestinal integrity depending on the antibiotic administered. To address this a total of 60 Wistar rats (housed in pairs with 6 cages per group were dosed by oral gavage with either amoxicillin (AMX, cefotaxime (CTX, vancomycin (VAN, metronidazole (MTZ, or water (CON daily for 10-11 days. Bacterial composition, alpha diversity and caecum short chain fatty acid levels were significantly affected by AMX, CTX and VAN, and varied among antibiotic treatments. A general decrease in diversity and an increase in the relative abundance of Proteobacteria was observed for all three antibiotics. Additionally, the relative abundance of Bifidobacteriaceae was increased in the CTX group and both Lactobacillaceae and Verrucomicrobiaceae were increased in the VAN group compared to the CON group. No changes in microbiota composition or function were observed following MTZ treatment. Intestinal permeability to 4 kDa FITC-dextran decreased after CTX and VAN treatment and increased following MTZ treatment. Plasma haptoglobin levels were increased by both AMX and CTX but no changes in expression of host tight junction genes were found in any treatment group. A strong correlation between the level of caecal succinate, the relative abundance of Clostridiaceae 1 family in the caecum, and the level of acute phase protein haptoglobin in blood plasma was observed. In conclusion, antibiotic-induced changes in microbiota may be linked to alterations in intestinal permeability, although the specific interactions remain to be elucidated as changes in

  13. Using computational models to relate structural and functional brain connectivity

    Czech Academy of Sciences Publication Activity Database

    Hlinka, Jaroslav; Coombes, S.

    2012-01-01

    Roč. 36, č. 2 (2012), s. 2137-2145 ISSN 0953-816X R&D Projects: GA MŠk 7E08027 EU Projects: European Commission(XE) 200728 - BRAINSYNC Institutional research plan: CEZ:AV0Z10300504 Keywords : brain disease * computational modelling * functional connectivity * graph theory * structural connectivity Subject RIV: FH - Neurology Impact factor: 3.753, year: 2012

  14. Permeability and dispersivity of variable-aperture fracture systems

    International Nuclear Information System (INIS)

    Tsang, Y.W.; Tsang, C.F.

    1990-01-01

    A number of recent experiments have pointed out the need of including the effects of aperture variation within each fracture in predicting flow and transport properties of fractured media. This paper introduces a new approach in which medium properties, such as the permeability to flow and dispersivity in tracer transport, are correlated to only three statistical parameters describing the fracture aperture probability distribution and the aperture spatial correlation. We demonstrate how saturated permeability and relative permeabilities for flow, as well as dispersion for solute transport in fractures may be calculated. We are in the process of examining the applicability of these concepts to field problems. Results from the evaluation and analysis of the recent Stripa-3D field data are presented. 13 refs., 10 figs

  15. An intelligent detecting system for permeability prediction of MBR.

    Science.gov (United States)

    Han, Honggui; Zhang, Shuo; Qiao, Junfei; Wang, Xiaoshuang

    2018-01-01

    The membrane bioreactor (MBR) has been widely used to purify wastewater in wastewater treatment plants. However, a critical difficulty of the MBR is membrane fouling. To reduce membrane fouling, in this work, an intelligent detecting system is developed to evaluate the performance of MBR by predicting the membrane permeability. This intelligent detecting system consists of two main parts. First, a soft computing method, based on the partial least squares method and the recurrent fuzzy neural network, is designed to find the nonlinear relations between the membrane permeability and the other variables. Second, a complete new platform connecting the sensors and the software is built, in order to enable the intelligent detecting system to handle complex algorithms. Finally, the simulation and experimental results demonstrate the reliability and effectiveness of the proposed intelligent detecting system, underlying the potential of this system for the online membrane permeability for detecting membrane fouling of MBR.

  16. Different Methods of Predicting Permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Krogsbøll, Anette

    by two to five orders of magnitudes at lower vertical effective stress below 40 MPa as the content of clay minerals increases causing heterogeneity in shale material. Indirect permeability from consolidation can give maximum and minimum values of shale permeability needed in simulating fluid flow......Permeability is often very difficult to measure or predict in shale lithology. In this work we are determining shale permeability from consolidation tests data using Wissa et al., (1971) approach and comparing the results with predicted permeability from Kozeny’s model. Core and cuttings materials...... effective stress to 9 μD at high vertical effective stress of 100 MPa. The indirect permeability calculated from consolidation tests falls in the same magnitude at higher vertical effective stress, above 40 MPa, as that of the Kozeny model for shale samples with high non-clay content ≥ 70% but are higher...

  17. Helicobacter Pylori Related Functional Dyspepsia in a Defined Malaysian Population

    OpenAIRE

    Nafeeza, M.I.; Isa, M.R.; Kudva, M.V.; Ishak, M.S.; Mazlam, M.Z.; Haron, A.; Najib, R.; Shahimi, M.M.

    2000-01-01

    The objective of the study was to determine the prevalence of H. pylori in functional dyspepsia among the three main races in Malaysia. Gastric antral biopsies from 233 (98 males, 135 females; age range: 17–75 years, mean age 39.5 years) patients attending the Universiti Kebangsaan Malaysia (UKM) gastroenterology clinic were assessed for the presence of H. pylori by culture and histology. About a third of the cases (79 of 233 (34%); 34 males, 45 females; mean age 42.6 yrs) were positive for H...

  18. [Age-related characteristics of structural support for ovarian function].

    Science.gov (United States)

    Koval'skiĭ, G B

    1984-12-01

    Histoenzymological assay was used to investigate various structures of the ovaries of rats of two groups aged 3-4 and 12-14 months during estral cycle. The activity of 3 beta-, 17 beta- and 20 alpha-steroid dehydrogenases, glucose-6-phosphate dehydrogenase, NAD and NADP-diaphorases, esterase, acid and alkaline phosphatases was studied. It has been shown that transport alterations in the microcirculation including the hematofollicular barrier play, the leading part in age-dependent depression of reproductive and endocrine functions. Ageing rats demonstrated no linkage between endothelial, thecal and granular cells, which points to the injury of the histophysiological mechanisms of the follicular system integration.

  19. Porosity, petrophysics and permeability of the Whitby Mudstone (UK)

    Science.gov (United States)

    Houben, M.; Barnhoorn, A.; Hardebol, N.; Ifada, M.; Boersma, Q.; Douma, L.; Peach, C. J.; Bertotti, G.; Drury, M. R.

    2016-12-01

    Typically pore diameters in shales range from the µm down to the nm scale and the effective permeability of shale reservoirs is a function of the interconnectivity between the pore space and the natural fracture network present. The length and spacing of mechanical induced and natural fractures is one of the factors controlling gas produtivity from unconventional reservoirs. Permeability of the Whitby Mudstone measured on 1 inch cores was linked to microstructure and combined with natural fracture spacing present in outcrops along the Yorkshire coast (UK) to get insight into possible fluid pathways from reservoir to well. We used a combination of different techniques to characterize the porosity (gas adsorption, Scanning Electron Microscopy), mineralogy (X-Ray Fluorescence, X-Ray Diffraction, Scanning Electron Microscopy) and permeability (pressure step decay) of the Whitby Mudstone. In addition, we mapped the natural fracture network as present in outcrops along the Yorkshire coast (UK) at the 10-2-101m scale. Mineralogically we are dealing with a rock that is high in clay content and has an average organic matter content of about 10%. Results show a low porosity (max. 7%) as well as low permeability for the Whitby Mudstone. The permeability, measured parallel to bedding, depends on the confining pressure and is 86 nanodarcy at 10 MPa effective confining pressure and decreases to 16 nanodarcy at 40 MPa effective confining pressure. At the scale of observation the average distance to nearest natural fracture is in the order of 0.13 meter and 90 percent of all matrix elements are spaced within 0.4 meter to the nearest fracture. By assuming darcy flow, a permeability of 100 nanodarcy and 10% of overpressure we calculated that for the Whitby mudstone most of the gas resides in the matrix for less than 60 days until it reaches the fracture network.

  20. Lower Limb Function in Elderly Korean Adults Is Related to Cognitive Function.

    Science.gov (United States)

    Kim, A-Sol; Ko, Hae-Jin

    2018-05-01

    Patients with cognitive impairment have decreased lower limb function. Therefore, we aimed to investigate the relationship between lower limb function and cognitive disorders to determine whether lower limb function can be screened to identify cognitive decline. Using Korean National Health Insurance Service-National Sample Cohort database data, we assessed the cognitive and lower limb functioning of 66-year-olds who underwent national health screening between 2010 and 2014. Cognitive function was assessed via a questionnaire. Timed Up-and-Go (TUG) and one-leg-standing (OLS) tests were performed to evaluate lower limb function. Associations between cognitive and lower limb functions were analyzed, and optimal cut-off points for these tests to screen for cognitive decline, were determined. Cognitive function was significantly correlated with TUG interval ( r = 0.414, p cognitive disorders were >11 s and ≤12 s for TUG interval and OLS duration, respectively. Among 66-year-olds who underwent national health screening, a significant correlation between lower limb and cognitive function was demonstrated. The TUG and OLS tests are useful screening tools for cognitive disorders in elderly patients. A large-scale prospective cohort study should be conducted to investigate the causal relationship between cognitive and lower limb function.

  1. Function-related Secondary User Needs and Secondary Data

    African Journals Online (AJOL)

    Riette Ruthven

    basis of both a critical analysis of the theory and an examination of selected data types .... (2) "Secondary needs related to the user's linguistic and subject-specific ... understand the Afrikaans word skepe needs to know that skepe is the plural.

  2. Methods and Algorithms for Approximating the Gamma Function and Related Functions. A survey. Part I: Asymptotic Series

    Directory of Open Access Journals (Sweden)

    Cristinel Mortici

    2015-01-01

    Full Text Available In this survey we present our recent results on analysis of gamma function and related functions. The results obtained are in the theory of asymptotic analysis, approximation of gamma and polygamma functions, or in the theory of completely monotonic functions. The motivation of this first part is the work of C. Mortici [Product Approximations via Asymptotic Integration Amer. Math. Monthly 117 (2010 434-441] where a simple strategy for constructing asymptotic series is presented. The classical asymptotic series associated to Stirling, Wallis, Glaisher-Kinkelin are rediscovered. In the second section we discuss some new inequalities related to Landau constants and we establish some asymptotic formulas.

  3. Neuropsychological function in relation to dysmenorrhea in adolescents.

    Science.gov (United States)

    Bahrami, Afsane; Sadeghnia, Hamidreza; Avan, Amir; Mirmousavi, Seyed Jamal; Moslem, Alireza; Eslami, Saeed; Heshmati, Masoud; Bahrami-Taghanaki, Hamidreza; Ferns, Gordon A; Ghayour-Mobarhan, Majid

    2017-08-01

    Hormonal variations during the menstrual cycle may affect emotional regulation. We aimed to investigate the association between dysmenorrhea (the severe abdominal pain and cramps associated with menstruation) and cognitive abilities, emotional function and sleep patterns in adolescent girls. Moreover, we evaluated the frequency of premenstrual syndrome (PMS) in our population and then divided them into 4 groups: subjects with only PMS; subjects with only dysmenorrhea; individuals with both PMS and dysmenorrhea and normal subjects. In this cross sectional study, 897 adolescent girls who had entered menarche were recruited. Of these, 35.9% had only dysmenorrhea, 14.9% had only PMS, 32.7% had both PMS and dysmenorrhea while 16.5% had no PMS and/or dysmenorrhea (Normal). We assessed the tests for cognitive, emotional function and sleep patterns were compared for these groups. Individuals in the dysmenorrhea group had significantly higher depression, aggression, insomnia, daytime sleepiness and sleep apnea scores compared to normal controls and the PMS group, but did not have significantly different cognitive ability (P value Dysmenorrhea is highly prevalent among adolescents and appears to be associated with depressive mood, a tendency to aggressive behavior and sleep disorders among adolescent girls. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Determination of Three-Phase Relative Permeabilities under Reservoir Conditions by Hot Water and Steamflood Experiments Détermination de perméabilités relatives tri-phasiques en conditions de réservoir, à partir d'expériences de balayages à l'eau chaude et à la vapeur

    Directory of Open Access Journals (Sweden)

    Quettier L.

    2006-11-01

    Full Text Available In order to help the physical and numerical interpretation of Emeraude's steam pilot, two-phase waterfloods at four temperatures (between 30 and 240°C and a steamflood were performed in the laboratory using the same porous medium (compacted silt and under reservoir conditions. Dynamic isothermal displacements were interpreted with a thermal simulator taking into account capillary end effects. The corresponding oil-water relative permeability curves were obtained by matching observed pressure drop and oil production. Results show that temperature influences the end-point saturations but not the shape of the curves. The steamflood experiment was carried out in an adiabatic core holder. Oil stripping and production of a large amount of CO2 caused by dissolution of carbonates were pointed out. The numerical interpretation of this experiment, by making use of the oil-water relative permeabilities, provided the three-phase oil relative permeability which is an essential datum for numerical interpretation of a steam drive pilot. Then a parameter study was used to quantify the influence of the different mechanisms involved in hot water and steam floods. Dans le but de faciliter l'interprétation physique et numérique du pilote vapeur d' Emeraude, des balayages eau-huile à quatre températures (entre 30 et 240°C et un balayage à la vapeur ont été réalisés au laboratoire. Toutes ces expériences ont été effectuées sur le même milieu poreux (silt compacté et en conditions de réservoir. Les déplacements bi-phasiques isothermes, en écoulement transitoire, ont été interprétés avec un modèle numérique thermique qui prend en compte les effets capillaires aux extrémités de l'échantillon. Les courbes de perméabilités relatives dynamiques eau-huile sont déterminées par calage, sur les courbes expérimentales, de la différence de pression et de la production d'huile simulées. Les résultats montrent que la température influe sur les

  5. The causes of functional psychoses as seen by patients and their relatives. II. The relatives' point of view.

    Science.gov (United States)

    Angermeyer, M C; Klusmann, D; Walpuski, O

    1988-01-01

    The concepts of relatives of patients suffering from functional psychoses regarding the causes of the illness were investigated using the same methodological approach as with the patients. Relatives, like patients, favoured psychosocial over biological explanations. However, when compared pairwise the concordance between relatives and patients was very low. Some methodological refinements recommended for further research are proposed.

  6. Low Permeability Polyimide Insulation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Resodyn Technologies proposes a new technology that enables the application of polyimide based cryogenic insulation with low hydrogen permeability. This effort...

  7. Modelling of water permeability in cementitious materials

    DEFF Research Database (Denmark)

    Guang, Ye; Lura, Pietro; van Breugel, K.

    2006-01-01

    This paper presents a network model to predict the permeability of cement paste from a numerical simulation of its microstructure. Based on a linked list pore network structure, the effective hydraulic conductivity is estimated and the fluid flow is calculated according to the Hagen-Poiseuille law....... The pressure gradient at all nodes is calculated with the Gauss elimination method and the absolute permeability of the pore network is calculated directly from Darcy's law. Finally, the permeability model is validated by comparison with direct water permeability measurements. According to this model...

  8. Intrinsically photosensitive retinal ganglion cell function in relation to age

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik

    2012-01-01

    The activity of melanopsin containing intrinsically photosensitive ganglion retinal cells (ipRGC) can be assessed by a means of pupil responses to bright blue (appr.480 nm) light. Due to age related factors in the eye, particularly, structural changes of the lens, less light reaches retina. The aim...... of this study was to examine how age and in vivo measured lens transmission of blue light might affect pupil light responses, in particular, mediated by the ipRGC....

  9. Relating form to function in the hummingbird feeding apparatus

    Directory of Open Access Journals (Sweden)

    Alejandro Rico-Guevara

    2017-06-01

    Full Text Available A complete understanding of the feeding structures is fundamental in order to study how animals survive. Some birds use long and protrusible tongues as the main tool to collect their central caloric source (e.g., woodpeckers and nectarivores. Hummingbirds are the oldest and most diverse clade of nectarivorous vertebrates, being a perfect subject to study tongue specializations. Their tongue functions to intraorally transport arthropods through their long bills and enables them to exploit the nectarivorous niche by collecting small amounts of liquid, therefore it is of vital importance to study its anatomy and structure at various scales. I focused on the portions of the hummingbird tongue that have been shown to be key for understanding their feeding mechanisms. I used histology, transmission and scanning electron microscopy, microCT, and ex-vivo experiments in order to advance the comprehension of the morphology and functioning of the hummingbird feeding apparatus. I found that hummingbird tongues are composed mainly of thin cornified epithelium, lack papillae, and completely fill the internal cast of the rostral oropharyngeal cavity. Understanding this puzzle-piece match between bill and tongue will be essential for the study of intraoral transport of nectar. Likewise, I found that the structural composition and tissue architecture of the tongue groove walls provide the rostral portion of the tongue with elastic properties that are central to the study of tongue-nectar interactions during the feeding process. Detailed studies on hummingbirds set the basis for comparisons with other nectar-feeding birds and contribute to comprehend the natural solutions to collecting liquids in the most efficient way possible.

  10. Relating form to function in the hummingbird feeding apparatus

    Science.gov (United States)

    2017-01-01

    A complete understanding of the feeding structures is fundamental in order to study how animals survive. Some birds use long and protrusible tongues as the main tool to collect their central caloric source (e.g., woodpeckers and nectarivores). Hummingbirds are the oldest and most diverse clade of nectarivorous vertebrates, being a perfect subject to study tongue specializations. Their tongue functions to intraorally transport arthropods through their long bills and enables them to exploit the nectarivorous niche by collecting small amounts of liquid, therefore it is of vital importance to study its anatomy and structure at various scales. I focused on the portions of the hummingbird tongue that have been shown to be key for understanding their feeding mechanisms. I used histology, transmission and scanning electron microscopy, microCT, and ex-vivo experiments in order to advance the comprehension of the morphology and functioning of the hummingbird feeding apparatus. I found that hummingbird tongues are composed mainly of thin cornified epithelium, lack papillae, and completely fill the internal cast of the rostral oropharyngeal cavity. Understanding this puzzle-piece match between bill and tongue will be essential for the study of intraoral transport of nectar. Likewise, I found that the structural composition and tissue architecture of the tongue groove walls provide the rostral portion of the tongue with elastic properties that are central to the study of tongue-nectar interactions during the feeding process. Detailed studies on hummingbirds set the basis for comparisons with other nectar-feeding birds and contribute to comprehend the natural solutions to collecting liquids in the most efficient way possible. PMID:28607842

  11. Migration of particulates in permeable rock columns

    International Nuclear Information System (INIS)

    Cropper, R.L.

    1982-01-01

    The migration of radioactive material through soil and permeable rock formations have become a major topic of concern due to the interest in the licensing of new radioactive waste disposal sites. Previously, research has been conducted in relation to deep repositories; however, similar situations arise in the vadose zone, where there is a higher probability of naturally-occurring particulates of organic nature and for the incursion of water. Test data has provided information which suggests that particulates will travel through porous media subject to various delay mechnisms and must be included in any consideration of waste migration. Data concerning particulate migration must and should be considered in the future when radioactive waste disposal sites are licensed

  12. Function-related secondary user needs and secondary data? a crit ...

    African Journals Online (AJOL)

    The aim of this article is to contribute to the development of the modern theory of lexicographical functions by offering a critical examination of the following concepts associated with it: primary needs, primary data, secondary needs, secondary data, function-related needs, and function-related data. By way of introduction, ...

  13. The impact of structural and functional characteristics of social relations as determinants of functional decline

    DEFF Research Database (Denmark)

    Avlund, Kirsten; Lund, Rikke; Holstein, Bjørn E

    2004-01-01

    ) and Glostrup (Denmark). The analyses are performed separately for men and women. Possible selection problems were considered by using three outcome measures: first, functional decline among the survivors (n = 425); second, functional decline, including death, assuming that death is part of a general decline...

  14. Visual steady state in relation to age and cognitive function

    DEFF Research Database (Denmark)

    Horwitz, Anna; Dyhr Thomsen, Mia; Wiegand, Iris

    2017-01-01

    Neocortical gamma activity is crucial for sensory perception and cognition. This study examines the value of using non-task stimulation-induced EEG oscillations to predict cognitive status in a birth cohort of healthy Danish males (Metropolit) with varying cognitive ability. In particular, we...... examine the steady-state VEP power response (SSVEP-PR) in the alpha (8Hz) and gamma (36Hz) bands in 54 males (avg. age: 62.0 years) and compare these with 10 young healthy participants (avg. age 27.6 years). Furthermore, we correlate the individual alpha-to-gamma difference in relative visual-area power...

  15. Sex Hormone-Related Functions in Regenerating Male Rat Liver

    Science.gov (United States)

    FRANCAVILLA, ANTONIO; EAGON, PATRICIA K.; DiLEO, ALFREDO; POLIMENO, LORENZO; PANELLA, CARMINE; AQUILINO, A. MARIA; INGROSSO, MARCELLO; Van THIEL, DAVID H.; STARZL, THOMAS E.

    2011-01-01

    Sex hormone receptors were quantitated in normal male rat liver and in regenerating liver at several different times after partial (70%) hepatectomy. Both estrogen and androgen receptor content were altered dramatically by partial hepatectomy. Total hepatic content and nuclear retention of estrogen receptors increased, with the zenith evident 2 days after partial hepatectomy, corresponding to the zenith of mitotic index. Serum estradiol increased after 1 day, and reached a maximum at 3 days after surgery. In contrast, total and nuclear androgen receptor content demonstrated a massive decline at 1, 2, and 3 days after resection. Serum testosterone displayed a parallel decline. In addition, hepatic content of two androgen-responsive proteins was reduced to 15% and 13% of normal values during this period. The activity of these various proteins during regeneration of male rat liver is comparable to that observed in the liver of normal female rats. Taken together, these results indicate that partial hepatectomy induces a feminization of certain sexually dimorphic aspects of liver function in male rats. Furthermore, these data provide evidence that estrogens, but not androgens, may have an important role in the process of liver regeneration. PMID:3758617

  16. [Neutron scatter studies of chromatin structure related to function

    International Nuclear Information System (INIS)

    Bradbury, E.M.

    1990-01-01

    This study is concerned with the application of neutron scatter techniques to the different structural states of nucleosomes and chromatin with the long term objective of understanding how the enormous lengths of DNA are folded into chromosomes. Micrococcal nuclease digestion kinetics have defined two subnucleosome particles; the chromatosome with 168 bp DNA, the histone octamer and one H1 and the nucleosome core particle with 146 bp DNA and the histone octamer. As will be discussed, the structure of the 146 bp DNA core particle is known in solution at low resolution from neutron scatter studies and in crystals. Based on this structure, the authors have a working model for the chromatosome and the mode of binding of H1. In order to define the structure of the nucleosome and also the different orders of chromatin structures they need to know the paths of DNA that link nucleosomes and the factors associated with chromosome functions that act on those DNA paths. The major region for this situation is the inherent variabilities in nucleosome DNA sequences, in the histone subtypes and their states of chemical modification and in the precise locations of nucleosomes. Such variabilities obscure the underlying principles that govern the packaging of DNA into the different structural states of nucleosomes and chromatin. The only way to elucidate these principles is to study the structures of nucleosomes and oligonucleosomes that are fully defined. They have largely achieved these objectives

  17. Development of functional food products in relation to obesity

    Directory of Open Access Journals (Sweden)

    Monika Choudhary

    2012-06-01

    Full Text Available Abstract:The development of new eating habits, as well as actual trends in production and consumption,has a health, environmental and social impact. The entire world is fighting diseases characteristic of the modern age such as obesity, osteoporosis, cancer, diabetes, allergies, and dental problems. With a global increase in the prevalence of obesity, both nutrition and exercise play key roles in its prevention and treatment. Natural product (nutraceutical interventions are currently being investigated on a large-scale basis as potential treatments for obesity and weight management. With advancing nutritional sciences, several nutrients such as; low-glycemic-indexcarbohydrates, 5-hydroxytryptophan, green tea extract, and chromium have been shown topromote weight loss. The first two nutrients decrease appetite, green tea increases the 24 hrenergy expenditure, and chromium promotes the composition of the weight lost to be fat rather than lean tissue. These have been assembled, in efficacious doses, into a new functional food product and described in this review. Each component has already been shown to promote weight loss independently in clinical trials.

  18. Function- and User-related Definitions in Online Dictionaries

    DEFF Research Database (Denmark)

    Nielsen, Sandro

    2011-01-01

    A study of the existing literature shows that definitions play an important part in dictionary use and making. The discussions primarily concern printed dictionaries and show that definitions are static in that only one definition should be provided for each meaning of a lemma or entry word, as a....... The important point is that each definition has been written with a specific function and user group in mind taking into account the needs of users in specific types of user situation.......A study of the existing literature shows that definitions play an important part in dictionary use and making. The discussions primarily concern printed dictionaries and show that definitions are static in that only one definition should be provided for each meaning of a lemma or entry word......, as argued in e.g. Jackson (2002: 86-100). However, online dictionaries provide lexicographers with the option of taking a more flexible approach to lexicographic definitions in an attempt to give the best possible help to users. The “one-size-fits-all” approach to dictionary making has its limits...

  19. Consolidation and permeability of salt in brine

    International Nuclear Information System (INIS)

    Shor, A.J.; Baes, C.F. Jr.; Canonico, C.M.

    1981-07-01

    The consolidation and loss of permeability of salt crystal aggregates, important in assessing the effects of water in salt repositories, has been studied as a function of several variables. The kinetic behavior was similar to that often observed in sintering and suggested the following expression for the time dependence of the void fraction: phi(t) = phi(0) - (A/B)ln(1 + Bt/z(0) 3 ), where A and B are rate constants and z(0) is initial average particle size. With brine present, A and phi(0) varied linearly with stress. The initial void fraction was also dependent to some extent on the particle size distribution. The rate of consolidation was most rapid in brine and least rapid in the presence of only air as the fluid. A brine containing 5 m MgCl 2 showed an intermediate rate, presumably because of the greatly reduced solubility of NaCl. A substantial wall effect was indicated by an observed increase in the void fraction of consolidated columns with distance from the top where the stress was applied and by a dependence of consolidation rate on the column height and radius. The distance through which the stress fell by a factor of phi was estimated to change inversely as the fourth power of the column diameter. With increasing temperature (to 85 0 C), consolidation proceeded somewhat more rapidly and the wall effect was reduced. The permeability of the columns dropped rapidly with consolidation, decreasing with about the sixth power of the void fraction. In general, extrapolation of the results to repository conditions confirms the self-sealing properties of bedded salt as a storage medium for radioactive waste

  20. Estimation of In Situ Stress and Permeability from an Extended Leak-off Test

    Science.gov (United States)

    Nghiep Quach, Quoc; Jo, Yeonguk; Chang, Chandong; Song, Insun

    2016-04-01

    stress regime with the information of the maximum principal stress that will be estimated based on borehole breakout geometry analysis. To estimate the in situ permeability from the XLOT data, we derived a theoretical equation that relates the slope of pressure versus injected water volume (P-V) curve to permeability based on the Darcy's law. The equation is expressed in terms of permeability as a function of some key parameters such as open-hole dimensions, flowrate, porosity, pressure change and injected water volume. We applied this equation to the early stage of the P-V curves prior to the leak-off point to prevent the effect of induced fractures on permeability. The estimated in situ permeability was (3.1±0.4)×10-17m2, which turns out to be quite similar to the laboratory measurements in recovered cores.

  1. Relative likelihood for life as a function of cosmic time

    Energy Technology Data Exchange (ETDEWEB)

    Loeb, Abraham [Astronomy department, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States); Batista, Rafael A.; Sloan, David, E-mail: aloeb@cfa.harvard.edu, E-mail: rafael.alvesbatista@physics.ox.ac.uk, E-mail: david.sloan@physics.ox.ac.uk [Department of Physics - Astrophysics, University of Oxford, DWB, Keble Road, OX1 3RH, Oxford (United Kingdom)

    2016-08-01

    Is life most likely to emerge at the present cosmic time near a star like the Sun? We address this question by calculating the relative formation probability per unit time of habitable Earth-like planets within a fixed comoving volume of the Universe, dP ( t )/ dt , starting from the first stars and continuing to the distant cosmic future. We conservatively restrict our attention to the context of ''life as we know it'' and the standard cosmological model, ΛCDM . We find that unless habitability around low mass stars is suppressed, life is most likely to exist near ∼ 0.1 M {sub ⊙} stars ten trillion years from now. Spectroscopic searches for biosignatures in the atmospheres of transiting Earth-mass planets around low mass stars will determine whether present-day life is indeed premature or typical from a cosmic perspective.

  2. Relative likelihood for life as a function of cosmic time

    International Nuclear Information System (INIS)

    Loeb, Abraham; Batista, Rafael A.; Sloan, David

    2016-01-01

    Is life most likely to emerge at the present cosmic time near a star like the Sun? We address this question by calculating the relative formation probability per unit time of habitable Earth-like planets within a fixed comoving volume of the Universe, dP ( t )/ dt , starting from the first stars and continuing to the distant cosmic future. We conservatively restrict our attention to the context of ''life as we know it'' and the standard cosmological model, ΛCDM . We find that unless habitability around low mass stars is suppressed, life is most likely to exist near ∼ 0.1 M ⊙ stars ten trillion years from now. Spectroscopic searches for biosignatures in the atmospheres of transiting Earth-mass planets around low mass stars will determine whether present-day life is indeed premature or typical from a cosmic perspective.

  3. On relation of momenta of structure functions of the composite systems with their simultaneous wave functions

    International Nuclear Information System (INIS)

    Linkevich, A.D.; Savrin, V.I.; Sanadze, V.V.; Skachkov, N.B.

    1984-01-01

    Calculation of hadron structure function (SF) comprising point objects is carried out. The obtained hadron SF is expressed by means of simultaneous relativistic wave functions of a composite particle. Exact calculation of hadron SF momenta in simultaneous formulation of quantum field theory off-energy surface is conducted. The given calculation of hadron SF is shown to result in their dependence on momentum transferred square (or square of total vector of energy-momentum of Compton scattering on a quark) whih is determined by the set of simultaneous hadron wave functions as bound state of quark (partons) in the considered case of non-structural quarks

  4. Complete Monotonicity of a Difference Between the Exponential and Trigamma Functions and Properties Related to a Modified Bessel Function

    DEFF Research Database (Denmark)

    Qi, Feng; Berg, Christian

    2013-01-01

    In the paper, the authors find necessary and sufficient conditions for a difference between the exponential function αeβ/t, α, β > 0, and the trigamma function ψ (t) to be completely monotonic on (0,∞). While proving the complete onotonicity, the authors discover some properties related to the fi...

  5. Intestinal permeability and nutritional status in developmental disorders.

    Science.gov (United States)

    Souza, Nilian Carla Silva; Mendonca, Jacqueline Nakau; Portari, Guilherme Vannucchi; Jordao Junior, Alceu Afonso; Marchini, Julio Sergio; Chiarello, Paula Garcia

    2012-01-01

    Autism is a developmental disorder with a possible connection between dietary components and triggering or worsening of symptoms. An altered intestinal permeability might allow absorption of incompletely digested peptides (gluten and casein) that could produce opioid-like activity on the brain, causing significant changes in behavior. To assess the intestinal permeability and nutritional status of participants with developmental disorders to determine if changes in the intestinal mucosal barrier and/or injury to the intercellular junctions have occurred that might justify application of further dietary modifications. To assess intestinal permeability, the research team analyzed participants urine under fasting conditions, using gas chromatography to determine chromatographic peaks. To assess nutritional status, the team determined participants heights and weights and performed a bioelectric bioimpedance examination at least 4 hours after their most recent meal. In addition, the team determined food intake using three diet diaries. They asked participants and caregivers to register each food consumed during 2 nonconsecutive weekdays and 1 weekend day. The study occurred at the Ribeirao Preto School of Medicine, Sao Paulo University. Seven participants aged 9 to 23 years with developmental disorders (the developmental group, DG) completed the study. The research team recruited them through the Association of Friends of the Autistic Persons of Ribeirao Preto in Ribeirao Preto, Brazil. The control group (CG) consisted of nonsmoking healthy volunteers in the general population who were similar in age to the experimental group and did not suffer from diseases that potentially could influence nutritional status and intestinal function. To assess intestinal permeability, participants ingested 150 mL of an isosmolar solution of the sugars mannitol (2 g) and lactulose (7.5 g) under fasting conditions and the researchers collected all voided urine over a period of 5 hours

  6. Experimental study on the soil structure and permeability in aerated zone at CIRP's field test site

    International Nuclear Information System (INIS)

    Du Zhongde; Zhao Yingjie; Guo Zhiming

    2000-01-01

    Measurement of soil grain and pore size distribution, observation of soil microstructure and permeability test are used to study soil structure and permeability. The results show that soil heterogeneity in vertical soil profile is much great. The mean heterogeneity coefficient is 14.7. The eccentric rate of saturated permeability coefficient in vertical and horizontal direction is from 0.65 to 1.00. The mean coefficient is 0.93. So the soil can be considered to be isotropic from the view point of the groundwater dynamics. The permeability coefficient has more difference in different soil layers. In vertical profile, the saturated permeability coefficient is relatively great in upper and under layers. It is relatively small in middle layers

  7. Absolute Monotonicity of Functions Related To Estimates of First Eigenvalue of Laplace Operator on Riemannian Manifolds

    Directory of Open Access Journals (Sweden)

    Feng Qi

    2014-10-01

    Full Text Available The authors find the absolute monotonicity and complete monotonicity of some functions involving trigonometric functions and related to estimates the lower bounds of the first eigenvalue of Laplace operator on Riemannian manifolds.

  8. What Health-Related Functions Are Regulated by the Nervous System?

    Science.gov (United States)

    ... What health-related functions are regulated by the nervous system? The nervous system plays a role in nearly every aspect of ... feeling emotions. Functions that are regulated by the nervous system include (but are not limited to): Brain growth ...

  9. Intestinal mucosal permeability of severely underweight and nonmalnourished Bangladeshi children and effects of nutritional rehabilitation.

    Science.gov (United States)

    Hossain, Md Iqbal; Nahar, Baitun; Hamadani, Jena D; Ahmed, Tahmeed; Roy, Anjan Kumar; Brown, Kenneth H

    2010-11-01

    Lactulose/mannitol (L/M) intestinal permeability tests were completed to compare the intestinal function of severely underweight children recovering from diarrhea and other illnesses and of nonmalnourished children from the same communities, and to evaluate the effects of food supplementation, with or without psychosocial stimulation, on the changes in intestinal function among the underweight children. Seventy-seven malnourished children completed intestinal permeability studies at baseline and 3 months after receiving 1 of the following randomly assigned treatment regimens: group-C--fortnightly follow-up at community-based follow-up units, including growth monitoring and promotion, health education, and micronutrient supplementation, n = 17; group-SF--same as group-C plus supplementary food (SF) to provide 150 to 300 kcal/day, n = 23; group-PS--same as group-C plus psychosocial stimulation (PS), n = 17; or group-SF + PS--same as group-C plus SF and PS, n = 20. Seventeen nonmalnourished children were included as comparison subjects. The malnourished children's mean ± SD initial age was 13.1 ± 4.0 months, their mean weight-for-age z score was -3.82 ± 0.61, and their median (interquartile range) urinary L/M recovery ratio was 0.16 (0.10-0.28). Eighty-four percent of the children had L/M ≥ 0.07, suggestive of impaired intestinal function. The median L/M of the malnourished children was significantly greater than that of 17 relatively well-nourished children (median 0.09; interquartile range 0.05-0.12; P = 0.001). There were no significant differences in baseline characteristics of the severely malnourished children by treatment group. Following treatment, the L/M ratio improved in all of the groups (P sugar permeability, is impaired among severely underweight children. Intestinal permeability improves in relation to weight gain, but intestinal mucosal recovery is not specifically related to the types or amount of food supplementation or PS provided in this trial.

  10. Endothelial glycocalyx dysfunction in disease: albuminuria and increased microvascular permeability.

    Science.gov (United States)

    Salmon, Andrew H J; Satchell, Simon C

    2012-03-01

    Appreciation of the glomerular microcirculation as a specialized microcirculatory bed, rather than as an entirely separate entity, affords important insights into both glomerular and systemic microvascular pathophysiology. In this review we compare regulation of permeability in systemic and glomerular microcirculations, focusing particularly on the role of the endothelial glycocalyx, and consider the implications for disease processes. The luminal surface of vascular endothelium throughout the body is covered with endothelial glycocalyx, comprising surface-anchored proteoglycans, supplemented with adsorbed soluble proteoglycans, glycosaminoglycans and plasma constituents. In both continuous and fenestrated microvessels, this endothelial glycocalyx provides resistance to the transcapillary escape of water and macromolecules, acting as an integral component of the multilayered barrier provided by the walls of these microvessels (ie acting in concert with clefts or fenestrae across endothelial cell layers, basement membranes and pericytes). Dysfunction of any of these capillary wall components, including the endothelial glycocalyx, can disrupt normal microvascular permeability. Because of its ubiquitous nature, damage to the endothelial glycocalyx alters the permeability of multiple capillary beds: in the glomerulus this is clinically apparent as albuminuria. Generalized damage to the endothelial glycocalyx can therefore manifest as both albuminuria and increased systemic microvascular permeability. This triad of altered endothelial glycocalyx, albuminuria and increased systemic microvascular permeability occurs in a number of important diseases, such as diabetes, with accumulating evidence for a similar phenomenon in ischaemia-reperfusion injury and infectious disease. The detection of albuminuria therefore has implications for the function of the microcirculation as a whole. The importance of the endothelial glycocalyx for other aspects of vascular function

  11. Wetting phase permeability in a partially saturated horizontal fracture

    International Nuclear Information System (INIS)

    Nicholl, M.J.; Glass, R.J.

    1994-01-01

    Fractures within geologic media can dominate the hydraulic properties of the system. Therefore, conceptual models used to assess the potential for radio-nuclide migration in unsaturated fractured rock such as that composing Yucca Mountain, Nevada, must be consistent with flow processes in individual fractures. A major obstacle to the understanding and simulation of unsaturated fracture flow is the paucity of physical data on both fracture aperture structure and relative permeability. An experimental procedure is developed for collecting detailed data on aperture and phase structure from a transparent analog fracture. To facilitate understanding of basic processes and provide a basis for development of effective property models, the simplest possible rough-walled fracture is used. Stable phase structures of varying complexity are created within the horizontal analog fracture. Wetting phase permeability is measured under steady-state conditions. A process based model for wetting phase relative permeability is then explored. Contributions of the following processes to reduced wetting phase permeability under unsaturated conditions are considered: reduction in cross-sectional flow area, increased path length, localized flow restriction, and preferential occupation of large apertures by the non-wetting phase

  12. Factors Influencing Stormwater Mitigation in Permeable Pavement

    Directory of Open Access Journals (Sweden)

    Chun Yan Liu

    2017-12-01

    Full Text Available Permeable pavement (PP is used worldwide to mitigate surface runoff in urban areas. Various studies have examined the factors governing the hydrologic performance of PP. However, relatively little is known about the relative importance of these governing factors and the long-term hydrologic performance of PP. This study applied numerical models—calibrated and validated using existing experimental results—to simulate hundreds of event-based and two long-term rainfall scenarios for two designs of PP. Based on the event-based simulation results, rainfall intensity, rainfall volume, thickness of the storage layer and the hydraulic conductivity of the subgrade were identified as the most influential factors in PP runoff reduction. Over the long term, PP performed significantly better in a relatively drier climate (e.g., New York, reducing nearly 90% of runoff volume compared to 70% in a relatively wetter climate (e.g., Hong Kong. The two designs of PP examined performed differently, and the difference was more apparent in the relatively wetter climate. This study generated insights that will help the design and implementation of PP to mitigate stormwater worldwide.

  13. Crustal permeability: Introduction to the special issue

    Science.gov (United States)

    Ingebritsen, Steven E.; Gleeson, Tom

    2015-01-01

    The topic of crustal permeability is of broad interest in light of the controlling effect of permeability on diverse geologic processes and also timely in light of the practical challenges associated with emerging technologies such as hydraulic fracturing for oil and gas production (‘fracking’), enhanced geothermal systems, and geologic carbon sequestration. This special issue of Geofluids is also motivated by the historical dichotomy between the hydrogeologic concept of permeability as a static material property that exerts control on fluid flow and the perspective of economic geologists, geophysicists, and crustal petrologists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. Issues associated with fracking, enhanced geothermal systems, and geologic carbon sequestration have already begun to promote a constructive dialog between the static and dynamic views of permeability, and here we have made a conscious effort to include both viewpoints. This special issue also focuses on the quantification of permeability, encompassing both direct measurement of permeability in the uppermost crust and inferential permeability estimates, mainly for the deeper crust.

  14. Soil gas measurements at high permeabilities and below foundation depth

    International Nuclear Information System (INIS)

    Johner, H.U; Surbeck, H.

    2000-01-01

    We started a project of soil gas measurements beneath houses. Since the foundations of houses often lie deeper than 0.5 to 1 m - the depth where soil gas measurements are often made - the first approach was to apply the method developed previously to deeper soil layers. The radon availability index (RAI), which was defined empirically, proved to be a reliable indicator for radon problems in nearby houses. The extreme values of permeability, non-Darcy flow and scale dependence of permeability stimulated the development of a multi-probe method. A hydrological model was applied to model the soil gas transport. The soil gas measurements below foundation depth provided a wealth of new information. A good classification of soil properties could be achieved. If soil gas measurements are to be made, the low permeability layer has to be traversed. A minimum depth of 1 .5 m is suggested, profiles to below the foundation depth are preferable. There are also implications for mitigation works. A sub-slab suction system should reach the permeable layer to function well. This also holds for radon wells. If a house is located on a slope, it is most convenient to install the sub-slab suction system on the hillside, as the foundation reaches the deepest levels there

  15. Development of an interstitial cystitis risk score for bladder permeability.

    Directory of Open Access Journals (Sweden)

    Laura E Lamb

    Full Text Available Interstitial cystitis/bladder pain syndrome (IC is a multifactorial syndrome of severe pelvic and genitalia pain and compromised urinary function; a subset of IC patients present with Hunner's lesions or ulcers on their bladder walls (UIC. UIC is diagnosed by cystoscopy, which may be quite painful. The objective of this study was to determine if a calculated Bladder Permeability Defect Risk Score (BP-RS based on non-invasive urinary cytokines could discriminate UIC patients from controls and IC patients without Hunner's ulcers.A national crowdsourcing effort targeted IC patients and age-matched controls to provide urine samples. Urinary cytokine levels for GRO, IL-6, and IL-8 were determined using a Luminex assay.We collected 448 urine samples from 46 states consisting of 153 IC patients (147 female, 6 male, of which 54 UIC patients (50 females, 4 male, 159 female controls, and 136 male controls. A defined BP-RS was calculated to classify UIC, or a bladder permeability defect etiology, with 89% validity.The BP-RS Score quantifies UIC risk, indicative of a bladder permeability defect etiology in a subset of IC patients. The Bladder Permeability Defect Risk Score is the first validated urine biomarker assay for interstitial cystitis/bladder pain syndrome.

  16. Sensing of Vascular Permeability in Inflamed Vessel of Live Animal

    Directory of Open Access Journals (Sweden)

    Sang A Park

    2018-01-01

    Full Text Available Increase in vascular permeability is a conclusive response in the progress of inflammation. Under controlled conditions, leukocytes are known to migrate across the vascular barriers to the sites of inflammation without severe vascular rupture. However, when inflammatory state becomes excessive, the leakage of blood components may occur and can be lethal. Basically, vascular permeability can be analyzed based on the intensity of blood outflow. To evaluate the amount and rate of leakage in live mice, we performed cremaster muscle exteriorization to visualize blood flow and neutrophil migration. Using two-photon intravital microscopy of the exteriorized cremaster muscle venules, we found that vascular barrier function is transiently and locally disrupted in the early stage of inflammatory condition induced by N-formylmethionyl-leucyl-phenylalanine (fMLP. Measurement of the concentration of intravenously (i.v. injected Texas Red dextran inside and outside the vessels resulted in clear visualization of real-time increases in transient and local vascular permeability increase in real-time manner. We successfully demonstrated repeated leakage from a target site on a blood vessel in association with increasing severity of inflammation. Therefore, compared to other methods, two-photon intravital microscopy more accurately visualizes and quantifies vascular permeability even in a small part of blood vessels in live animals in real time.

  17. Adaptive Methods for Permeability Estimation and Smart Well Management

    Energy Technology Data Exchange (ETDEWEB)

    Lien, Martha Oekland

    2005-04-01

    indicators, are described in Chapter 3. In Chapter 4, we give an introduction to level set functions as a tool to solve geometric inverse problems. Permeability estimation is the topic of Chapter 5. This includes an introduction of different data sources and a discussion about error and identifiability of the estimated parameters. An introduction to the proposed combination of adaptive multiscale estimation and level set functions for absolute permeability estimation is also given. In Chapter 6, we present water flood optimization by means of smart wells in the framework of optimal control theory. Here, hierarchical regularization methods are introduced to this problem, i.e. multiscale estimation and refinement indicators. Based on the theory presented in the previous chapters, summaries of the Based on the theory presented in the previous chapters, summaries of the research papers are given in Chapter 7. Part II: In Part II, four research papers are presented.

  18. Effects of temperature, mechanical loading and of their interactions on the permeability of structural concrete

    International Nuclear Information System (INIS)

    Choinska, M.

    2006-11-01

    Concrete permeability may influence the durability of structures indirectly by controlling the penetration rate of aggressive agents, but also directly if the structure has a confinement role, like containment vessels of nuclear power plants for instance. In the industrial background on the safety of these structures, the objective of this study is to characterize the evolution of concrete permeability under the effects of temperature and mechanical loading. The permeability tests are performed on hollow concrete cylinders, subjected to temperature up to 150 C and compressive loading up to failure. Experimental results reveal that the effects of temperature and damage may be decoupled for the estimation of permeability and enable us to propose a relation between permeability, damage and temperature. However, this relation may only be applied in the pre-peak phase as concrete remains micro-cracked. In order to overcome this limit to be able to model also permeability increase in the post-peak phase, another parameter, which is crack opening, is introduced in the relation between permeability and damage. This problem, investigated by modelling, is exploited according to two approaches. The first one is based on the definition of a matching law between existing relations of permeability evolution with damage and with crack opening. With this approach the tendencies are similar to the observed ones on the experimental results. The second approach consists in linking from a mechanical point of view damage with crack opening in order to apply the Poiseuille's law for permeability determination. Experimental validation of this approach, emerging towards a continuous model capable to reproduce permeability variations of a concrete structure, constitutes a major perspective of this work. (author)

  19. Wave transmission over permeable submerged breakwaters; Transmision del oleaje en rompeolas sumergidos permeables

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-y-Zurvia-Flores, Jaime Roberto; Fragoso-Sandoval, Lucio [Instituto Politecnico Nacional(Mexico)

    2008-10-15

    The permeable submerged breakwaters represent a coastal protection alternative, where some degree of wave energy transmission is acceptable. Such would be the case of tourist beach protection in Mexico. In previous researches, like those performed by D'Angremond et al. (1996), Seabrook and Hall (1998), and Briganti et al. (2003), the empirical formulas developed, give only some limited information over the spatial distribution of wave energy over the structure. Therefore, a decision was made to conduct a study on a reduced physical model of a permeable submerged breakwater based on the results presented by those researchers and with possible applications. Therefore this paper presents the development of a study of wave transmission over permeable submerged breakwaters performed in a reduced physical model of different sections of a submerged rockfill breakwater of the trapezoidal type. This was done in a narrow wave flume with a hydraulic irregular wave generator controlled by a computer that was used to generate and to reproduce different types of irregular waves to be used in the tests. It also has a wave meter with four sensors, and they are connected to a computer in order to process the wave data. The main objective of the study was to determine in an experimental way the influence of the several parameters of submerged breakwater over the wave transmission coefficient. Our experimental results were comparable to those obtained by D'Angremond et al. (1996) and Seabrook and Hall (1998). The results show that the sumerged breakwater parameters of most influence over the wave transmission coefficient were relative submergence and the relative width crest of the sumerged breakwater, and that the formula by Seabrook and Hall correlates best with our results. [Spanish] Los rompeolas sumergidos permeables representan actualmente una alternativa de proteccion de costas, donde un cierto grado de transmision de energia del oleaje es aceptable, como seria el

  20. Colloid transport in dual-permeability media

    Science.gov (United States)

    Leij, Feike J.; Bradford, Scott A.

    2013-07-01

    It has been widely reported that colloids can travel faster and over longer distances in natural structured porous media than in uniform structureless media used in laboratory studies. The presence of preferential pathways for colloids in the subsurface environment is of concern because of the increased risks for disease caused by microorganisms and colloid-associated contaminants. This study presents a model for colloid transport in dual-permeability media that includes reversible and irreversible retention of colloids and first-order exchange between the aqueous phases of the two regions. The model may also be used to describe transport of other reactive solutes in dual-permeability media. Analytical solutions for colloid concentrations in aqueous and solid phases were obtained using Laplace transformation and matrix decomposition. The solutions proved convenient to assess the effect of model parameters on the colloid distribution. The analytical model was used to describe effluent concentrations for a bromide tracer and 3.2- or 1-μm-colloids that were observed after transport through a composite 10-cm long porous medium made up of a cylindrical lens or core of sand and a surrounding matrix with sand of a different grain size. The tracer data were described very well and realistic estimates were obtained for the pore-water velocity in the two flow domains. An accurate description was also achieved for most colloid breakthrough curves. Dispersivity and retention parameters were typically greater for the larger 3.2-μm-colloids while both reversible and irreversible retention rates tended to be higher for the finer sands than the coarser sand. The relatively small sample size and the complex flow pattern in the composite medium made it difficult to reach definitive conclusions regarding transport parameters for colloid transport.

  1. A permeability model for coal and other fractured, sorptive-elastic media

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, E.P.; Christiansen, R.L. [Marathon Oil Co., Houston, TX (United States). Research & Development Facility

    2008-09-15

    This paper describes the derivation of a new equation that can be used to model the permeability behavior of a fractured, sorptive-elastic medium, such as coal, under variable stress conditions. The equation is applicable to confinement pressure schemes commonly used during the collection of permeability data in the laboratory. The model is derived for cubic geometry under biaxial or hydrostatic confining pressures. The model is designed to handle changes in permeability caused by adsorption and desorption of gases onto and from the matrix blocks in fractured media. The model equations can be used to calculate permeability changes caused by the production of methane (CH{sub 4}) from coal as well as the injection of gases, such as carbon dioxide, for sequestration in coal. Sensitivity analysis of the model found that each of the input variables can have a significant impact on the outcome of the permeability forecast as a function of changing pore pressure, thus, accurate input data are essential. The permeability model also can be used as a tool to determine input parameters for field simulations by curve fitting laboratory-generated permeability data. The new model is compared to two other widely used coal-permeability models using a hypothetical coal with average properties.

  2. Effect of temperature on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Kjøller, Claus

    Hot water injection in geothermal sandstone aquifers is considered for seasonal energy storage in Denmark. However, an increase in the aquifer temperature might reduce permeability, and thereby increase production costs. An understanding of the factors that control permeability is required in order...... and the Klinkenberg procedure showed the expected correlation between the two measures, however, differences could be around one order of magnitude. In tight gas sandstones, permeability is often sensitive to net stress, which might change due to the pore pressure change in the Klinkenberg procedure. Besides...... affecting the Klinkenberg procedure, the combined effect of slip and changes in permeability would affect production during pressure depletion in tight gas sandstone reservoirs; therefore effects of gas slip and net stress on permeability were combined in a model based on the Klinkenberg equation. A lower...

  3. Microorganism Removal in Permeable Pavement Parking Lots ...

    Science.gov (United States)

    Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers. Concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard. Fecal coliform and enterococci exceeded bathing water quality standards more than 72% and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Purpose is to evaluate the performance of permeable pavement in removing indicator organisms from infiltrating stormwater runoff.

  4. Hypothalamic-pituitary-gonadal function in relation to liver function in men with alcoholic cirrhosis

    DEFF Research Database (Denmark)

    Gluud, C; Bahnsen, M; Bennett, Patrick

    1983-01-01

    ). No significant difference was observed when comparing serum testosterone concentrations. Patients were divided into three groups in accordance with the severity of liver cirrhosis, using biochemical and clinical criteria. Patients with the best-preserved liver function (no. = 11) and patients with moderately...... affected liver function (no. = 18) had significantly (P less than 0.05) raised serum concentrations of testosterone, FSH, and LH when compared with both controls and patients with severely affected liver function (no. = 13). Serum concentrations of testosterone, FSH, and LH in the latter group showed...... groups of patients. Dexamethasone suppression did not change the concentration of testosterone significantly, but oestrone and oestradiol concentrations decreased significantly (P less than 0.01) in controls and patients. In patients, but not in controls, a significant (P less than 0.01) increase in FSH...

  5. Use of geophysical logs to estimate the quality of ground water and the permeability of aquifers

    Science.gov (United States)

    Hudson, J.D.

    1996-01-01

    The relation of formation factor to resistivity of formation water and intergranular permeability has often been investigated, and the general consensus is that this relation is closest when established in a clean-sand aquifer in which water quality does not vary substantially. When these restrictions are applied, the following standard equation is a useful tool in estimating the resistance of the formation water: F = Ro/Rw, where F is the formation factor, which is a function of the effective porosity; Ro is the resistivity of a formation that is 100 percent saturated with interstitial water; and Rw is the resistivity of the water in the saturated zone. However, arenaceous aquifers can have electrical resistivities that are not directly related to resistivity of water or porosity. Surface conductivity and ion exchange are significant factors when the sediments are clay bearing. The solid constituents are a major component of the parameters needed to solve the equation for formation-water resistivity and estimates of aquifer permeability. A correction process needs to be applied to adjust the variables, Ro and F, to the equivalent of clean sand. This report presents an empirical method of using the neutron log and the electrical-resistivity values from long- and short-normal resistivity logs to correct for fine-grained material and the subsequent effects of low impedance to electrical flow that are not related to the resistance of formation water.

  6. Permeability During Magma Expansion and Compaction

    Science.gov (United States)

    Gonnermann, Helge. M.; Giachetti, Thomas; Fliedner, Céline; Nguyen, Chinh T.; Houghton, Bruce F.; Crozier, Joshua A.; Carey, Rebecca J.

    2017-12-01

    Plinian lapilli from the 1060 Common Era Glass Mountain rhyolitic eruption of Medicine Lake Volcano, California, were collected and analyzed for vesicularity and permeability. A subset of the samples were deformed at a temperature of 975°, under shear and normal stress, and postdeformation porosities and permeabilities were measured. Almost all undeformed samples fall within a narrow range of vesicularity (0.7-0.9), encompassing permeabilities between approximately 10-15 m2 and 10-10 m2. A percolation threshold of approximately 0.7 is required to fit the data by a power law, whereas a percolation threshold of approximately 0.5 is estimated by fitting connected and total vesicularity using percolation modeling. The Glass Mountain samples completely overlap with a range of explosively erupted silicic samples, and it remains unclear whether the erupting magmas became permeable at porosities of approximately 0.7 or at lower values. Sample deformation resulted in compaction and vesicle connectivity either increased or decreased. At small strains permeability of some samples increased, but at higher strains permeability decreased. Samples remain permeable down to vesicularities of less than 0.2, consistent with a potential hysteresis in permeability-porosity between expansion (vesiculation) and compaction (outgassing). We attribute this to retention of vesicle interconnectivity, albeit at reduced vesicle size, as well as bubble coalescence during shear deformation. We provide an equation that approximates the change in permeability during compaction. Based on a comparison with data from effusively erupted silicic samples, we propose that this equation can be used to model the change in permeability during compaction of effusively erupting magmas.

  7. Sex-related differences in amygdala functional connectivity during resting conditions.

    Science.gov (United States)

    Kilpatrick, L A; Zald, D H; Pardo, J V; Cahill, L F

    2006-04-01

    Recent neuroimaging studies have established a sex-related hemispheric lateralization of amygdala involvement in memory for emotionally arousing material. Here, we examine the possibility that sex-related differences in amygdala involvement in memory for emotional material develop from differential patterns of amygdala functional connectivity evident in the resting brain. Seed voxel partial least square analyses of regional cerebral blood flow data revealed significant sex-related differences in amygdala functional connectivity during resting conditions. The right amygdala was associated with greater functional connectivity in men than in women. In contrast, the left amygdala was associated with greater functional connectivity in women than in men. Furthermore, the regions displaying stronger functional connectivity with the right amygdala in males (sensorimotor cortex, striatum, pulvinar) differed from those displaying stronger functional connectivity with the left amygdala in females (subgenual cortex, hypothalamus). These differences in functional connectivity at rest may link to sex-related differences in medical and psychiatric disorders.

  8. Permeability coefficient of proton irradiated polyethylene terephatalate thin films

    International Nuclear Information System (INIS)

    Bassani, L.C.; Santos, W.M.S.; Marechal, B.

    1983-01-01

    The principle of operation of an apparatus developed to study gas permation through thin films is described and the measurement method is discussed. Use is made of diffusion theory to obtain a expression for the permeability coefficient as a function of the rate of increase of the pressure in the receiving volume. The Gibbs function for permeation of Helium through Polyethylene Terephtalate (P.E.T.) is determined. The permeability coefficient of Helium is found to increase significantly with the range of the implanted protons although the incident charge has been kept constant. The hypothesis of structural modifications of the proton implanted P.E.T. seems to be confirmed by small angles X-rays scattering experiments on the irradiated samples. (Author) [pt

  9. An asymptotic model of seismic reflection from a permeable layer

    Energy Technology Data Exchange (ETDEWEB)

    Silin, D.; Goloshubin, G.

    2009-10-15

    Analysis of compression wave propagation in a poroelastic medium predicts a peak of reflection from a high-permeability layer in the low-frequency end of the spectrum. An explicit formula expresses the resonant frequency through the elastic moduli of the solid skeleton, the permeability of the reservoir rock, the fluid viscosity and compressibility, and the reservoir thickness. This result is obtained through a low-frequency asymptotic analysis of Biot's model of poroelasticity. A review of the derivation of the main equations from the Hooke's law, momentum and mass balance equations, and Darcy's law suggests an alternative new physical interpretation of some coefficients of the classical poroelasticity. The velocity of wave propagation, the attenuation factor, and the wave number, are expressed in the form of power series with respect to a small dimensionless parameter. The absolute value of this parameter is equal to the product of the kinematic reservoir fluid mobility and the wave frequency. Retaining only the leading terms of the series leads to explicit and relatively simple expressions for the reflection and transmission coefficients for a planar wave crossing an interface between two permeable media, as well as wave reflection from a thin highly-permeable layer (a lens). Practical applications of the obtained asymptotic formulae are seismic modeling, inversion, and at-tribute analysis.

  10. Trench infiltration for managed aquifer recharge to permeable bedrock

    Science.gov (United States)

    Heilweil, V.M.; Watt, D.E.

    2011-01-01

    Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge in southwestern Utah have recently been implemented to meet growth-related water demands. This paper reports on a new cost-effective surface-infiltration technique utilizing trenches for enhancing managed aquifer recharge to permeable bedrock. A 48-day infiltration trench experiment on outcropping Navajo Sandstone was conducted to evaluate this alternative surface-spreading artificial recharge method. Final infiltration rates through the bottom of the trench were about 0.5 m/day. These infiltration rates were an order of magnitude higher than rates from a previous surface-spreading experiment at the same site. The higher rates were likely caused by a combination of factors including the removal of lower permeability soil and surficial caliche deposits, access to open vertical sandstone fractures, a reduction in physical clogging associated with silt and biofilm layers, minimizing viscosity effects by maintaining isothermal conditions, minimizing chemical clogging caused by carbonate mineral precipitation associated with algal photosynthesis, and diminished gas clogging associated with trapped air and biogenic gases. This pilot study illustrates the viability of trench infiltration for enhancing surface spreading of managed aquifer recharge to permeable bedrock. ?? 2010.

  11. Hypothalamic-pituitary-gonadal function in relation to liver function in men with alcoholic cirrhosis

    DEFF Research Database (Denmark)

    Gluud, C; Bahnsen, M; Bennett, Patrick

    1983-01-01

    Serum concentrations of oestrone, oestradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) were significantly (P less than 0.01) raised in men with alcoholic liver cirrhosis (no. = 42) compared with age-matched controls (no. = 20). No signi......Serum concentrations of oestrone, oestradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) were significantly (P less than 0.01) raised in men with alcoholic liver cirrhosis (no. = 42) compared with age-matched controls (no. = 20...... affected liver function (no. = 18) had significantly (P less than 0.05) raised serum concentrations of testosterone, FSH, and LH when compared with both controls and patients with severely affected liver function (no. = 13). Serum concentrations of testosterone, FSH, and LH in the latter group showed...

  12. Harris functional and related methods for calculating total energies in density-functional theory

    International Nuclear Information System (INIS)

    Averill, F.W.; Painter, G.S.

    1990-01-01

    The simplified energy functional of Harris has given results of useful accuracy for systems well outside the limits of weakly interacting fragments for which the method was originally proposed. In the present study, we discuss the source of the frequent good agreement of the Harris energy with full Kohn-Sham self-consistent results. A procedure is described for extending the applicability of the scheme to more strongly interacting systems by going beyond the frozen-atom fragment approximation. A gradient-force expression is derived, based on the Harris functional, which accounts for errors in the fragment charge representation. Results are presented for some diatomic molecules, illustrating the points of this study

  13. An efficient permeability scaling-up technique applied to the discretized flow equations

    Energy Technology Data Exchange (ETDEWEB)

    Urgelli, D.; Ding, Yu [Institut Francais du Petrole, Rueil Malmaison (France)

    1997-08-01

    Grid-block permeability scaling-up for numerical reservoir simulations has been discussed for a long time in the literature. It is now recognized that a full permeability tensor is needed to get an accurate reservoir description at large scale. However, two major difficulties are encountered: (1) grid-block permeability cannot be properly defined because it depends on boundary conditions; (2) discretization of flow equations with a full permeability tensor is not straightforward and little work has been done on this subject. In this paper, we propose a new method, which allows us to get around both difficulties. As the two major problems are closely related, a global approach will preserve the accuracy. So, in the proposed method, the permeability up-scaling technique is integrated in the discretized numerical scheme for flow simulation. The permeability is scaled-up via the transmissibility term, in accordance with the fluid flow calculation in the numerical scheme. A finite-volume scheme is particularly studied, and the transmissibility scaling-up technique for this scheme is presented. Some numerical examples are tested for flow simulation. This new method is compared with some published numerical schemes for full permeability tensor discretization where the full permeability tensor is scaled-up through various techniques. Comparing the results with fine grid simulations shows that the new method is more accurate and more efficient.

  14. Comparison of Mass Transfer Models for Determination of the Intestinal Permeability

    Directory of Open Access Journals (Sweden)

    P Zakeri-Milani

    2008-09-01

    Full Text Available Background and the purpose of the study: In determination of the permeability of the intestinal wall by external perfusion techniques, several models have been proposed. In the present study three models were used for experimental results that differ in their convection and diffusion assumptions. Material and Methods: Permeability coefficients for 13 compounds (metoprolol, propranolol, naproxen, ketoprofen, furosemide, hydrochlorothiazide, cimetidine, ranitidine, atenolol, piroxicam, antipyrine, ibuprofen and carbamazepine with known human intestinal permeability values were determined in anaesthetized rats by different mass transfer models and plotted versus the observed human intestinal permeabilities. Results: The calculated dimensionless wall permeability values were in the range of 0.37 - 4.85, 0.38-6.54 and 0.41-16.59 for complete radial mixing, mixing tank and laminar flow models respectively. The results indicated that all of the models work relatively well for our data despite fundamentally different assumptions. The wall permeabilities were in the order laminar flow > mixing tank > complete radial mixing. Conclusion: Although laminar flow model provides the most direct measure of the intrinsic wall permeability, it has limitations for highly permeable drugs such as ibuprofen. The normal physiological hydrodynamics is more complex and more investigation is required to find out the real hydrodynamics.

  15. Increased gut permeability in cancer cachexia: mechanisms and clinical relevance.

    Science.gov (United States)

    Bindels, Laure B; Neyrinck, Audrey M; Loumaye, Audrey; Catry, Emilie; Walgrave, Hannah; Cherbuy, Claire; Leclercq, Sophie; Van Hul, Matthias; Plovier, Hubert; Pachikian, Barbara; Bermúdez-Humarán, Luis G; Langella, Philippe; Cani, Patrice D; Thissen, Jean-Paul; Delzenne, Nathalie M

    2018-04-06

    Intestinal disorders often occur in cancer patients, in association with body weight loss, and this alteration is commonly attributed to the chemotherapy. Here, using a mouse model of cancer cachexia induced by ectopic transplantation of C26 cancer cells, we discovered a profound alteration in the gut functions (gut permeability, epithelial turnover, gut immunity, microbial dysbiosis) independently of any chemotherapy. These alterations occurred independently of anorexia and were driven by interleukin 6. Gut dysfunction was found to be resistant to treatments with an anti-inflammatory bacterium ( Faecalibacterium prausnitzii ) or with gut peptides involved in intestinal cell renewal (teduglutide, a glucagon-like peptide 2 analogue). The translational value of our findings was evaluated in 152 colorectal and lung cancer patients with or without cachexia. The serum level of the lipopolysaccharide-binding protein, often presented as a reflection of the bacterial antigen load, was not only increased in cachectic mice and cancer patients, but also strongly correlated with the serum IL-6 level and predictive of death and cachexia occurrence in these patients. Altogether, our data highlight profound alterations of the intestinal homeostasis in cancer cachexia occurring independently of any chemotherapy and food intake reduction, with potential relevance in humans. In addition, we point out the lipopolysaccharide-binding protein as a new biomarker of cancer cachexia related to gut dysbiosis.

  16. Generalized relations among N-dimensional Coulomb Green's functions using fractional derivatives

    International Nuclear Information System (INIS)

    Blinder, S.M.; Pollock, E.L.

    1989-01-01

    Hostler [J. Math. Phys. 11, 2966 (1970)] has shown that Coulomb Green's functions of different dimensionality N are related by G (N+2) =OG (N) , where O is a first-order derivative operator in the variables x and y. Thus all the even-dimensional functions are connected, as are analogously the odd-dimensional functions. It is shown that the operations of functional differentiation and integration can further connect the even- to the odd-dimensional functions, so that Hostler's relation can be extended to give G (N+1) =O 1/2 G (N)

  17. Verbal Memory Deficits in Relation to Organization Strategy in High- and Low-Functioning Autistic Children

    Science.gov (United States)

    Cheung, Mei-chun; Chan, Agnes S.; Sze, Sophia L.; Leung, Winnie W.; To, Cho Yee

    2010-01-01

    The present study examined the verbal memory profile and its relation to organizational strategies in high-functioning (Hi-AUT) and low-functioning (Lo-AUT) children with autism. Twenty-two Hi-AUT and 16 Lo-AUT, and 22 age-, gender- and handedness-matched normal children (NC) were required to remember a list of semantically related words for…

  18. Degenerate T coefficients and their relation to Wigner's 3j symbols and the D function

    International Nuclear Information System (INIS)

    Kuznetsov, G.I.; Smorodinskij, Ya.A.

    1977-01-01

    On basis of various representations of the T coefficients and using limiting procedures, var//uios degenerate cases are studied for these coefficients and their relation This enables one to find relations between the hypergeometric function 4 F 3 (....1) and the functions 3 F 2 (...1) and 2 F 1 (...1/2)

  19. Permeability Barrier Generation in the Martian Lithosphere

    Science.gov (United States)

    Schools, Joe; Montési, Laurent

    2015-11-01

    Permeability barriers develop when a magma produced in the interior of a planet rises into the cooler lithosphere and crystallizes more rapidly than the lithosphere can deform (Sparks and Parmentier, 1991). Crystallization products may then clog the porous network in which melt is propagating, reducing the permeability to almost zero, i.e., forming a permeability barrier. Subsequent melts cannot cross the barrier. Permeability barriers have been useful to explain variations in crustal thickness at mid-ocean ridges on Earth (Magde et al., 1997; Hebert and Montési, 2011; Montési et al., 2011). We explore here under what conditions permeability barriers may form on Mars.We use the MELTS thermodynamic calculator (Ghiorso and Sack, 1995; Ghiorso et al., 2002; Asimow et al., 2004) in conjunction with estimated Martian mantle compositions (Morgan and Anders, 1979; Wänke and Dreibus, 1994; Lodders and Fegley, 1997; Sanloup et al., 1999; Taylor 2013) to model the formation of permeability barriers in the lithosphere of Mars. In order to represent potential past and present conditions of Mars, we vary the lithospheric thickness, mantle potential temperature (heat flux), oxygen fugacity, and water content.Our results show that permeability layers can develop in the thermal boundary layer of the simulated Martian lithosphere if the mantle potential temperature is higher than ~1500°C. The various Martian mantle compositions yield barriers in the same locations, under matching variable conditions. There is no significant difference in barrier location over the range of accepted Martian oxygen fugacity values. Water content is the most significant influence on barrier development as it reduces the temperature of crystallization, allowing melt to rise further into the lithosphere. Our lower temperature and thicker lithosphere model runs, which are likely the most similar to modern Mars, show no permeability barrier generation. Losing the possibility of having a permeability

  20. Age-related normal structural and functional ventricular values in cardiac function assessed by magnetic resonance

    International Nuclear Information System (INIS)

    Fiechter, Michael; Gaemperli, Oliver; Kaufmann, Philipp A; Fuchs, Tobias A; Gebhard, Catherine; Stehli, Julia; Klaeser, Bernd; Stähli, Barbara E; Manka, Robert; Manes, Costantina; Tanner, Felix C

    2013-01-01

    The heart is subject to structural and functional changes with advancing age. However, the magnitude of cardiac age-dependent transformation has not been conclusively elucidated. This retrospective cardiac magnetic resonance (CMR) study included 183 subjects with normal structural and functional ventricular values. End systolic volume (ESV), end diastolic volume (EDV), and ejection fraction (EF) were obtained from the left and the right ventricle in breath-hold cine CMR. Patients were classified into four age groups (20–29, 30–49, 50–69, and ≥70 years) and cardiac measurements were compared using Pearson’s rank correlation over the four different groups. With advanced age a slight but significant decrease in ESV (r=−0.41 for both ventricles, P<0.001) and EDV (r=−0.39 for left ventricle, r=−0.35 for right ventricle, P<0.001) were observed associated with a significant increase in left (r=0.28, P<0.001) and right (r=0.27, P<0.01) ventricular EF reaching a maximal increase in EF of +8.4% (P<0.001) for the left and +6.1% (P<0.01) for the right ventricle in the oldest compared to the youngest patient group. Left ventricular myocardial mass significantly decreased over the four different age groups (P<0.05). The aging process is associated with significant changes in left and right ventricular EF, ESV and EDV in subjects with no cardiac functional and structural abnormalities. These findings underline the importance of using age adapted values as standard of reference when evaluating CMR studies

  1. Generating relations of multi-variable Tricomi functions of two indices using Lie algebra representation

    Directory of Open Access Journals (Sweden)

    Nader Ali Makboul Hassan

    2014-01-01

    Full Text Available This paper is an attempt to stress the usefulness of the multi-variable special functions. In this paper, we derive certain generating relations involving 2-indices 5-variables 5-parameters Tricomi functions (2I5V5PTF by using a Lie-algebraic method. Further, we derive certain new and known generating relations involving other forms of Tricomi and Bessel functions as applications.

  2. Probability laws related to the Jacobi theta and Riemann zeta function and Brownian excursions

    OpenAIRE

    Biane, P.; Pitman, J.; Yor, M.

    1999-01-01

    This paper reviews known results which connect Riemann's integral representations of his zeta function, involving Jacobi's theta function and its derivatives, to some particular probability laws governing sums of independent exponential variables. These laws are related to one-dimensional Brownian motion and to higher dimensional Bessel processes. We present some characterizations of these probability laws, and some approximations of Riemann's zeta function which are related to these laws.

  3. Functional ability of community dwelling elderly. Criterion-related validity of a new measure of functional ability

    DEFF Research Database (Denmark)

    Schultz-Larsen, K; Avlund, K; Kreiner, S

    1992-01-01

    Criterion-related validity of a new measure of functional ability was conducted according to a causal model based on conceptual models employed in the area of rehabilitative and geriatric medicine. The criteria variables included concurrent diagnosed diseases, global self-rated health, drug...... consumption and general practitioner (GP) consultations. The measure of functional ability was developed with the intention of achieving a high degree of discrimination among a group of community dwelling elderly. Data were derived from a sample survey of 70-year-old men and women conducted in 1984...... different unidimensional index scales of functional ability divided into two types, with reduced speed and tiredness as subdimensions. The two scale types were mobility function and lower limb function. Early losses of ability together with global self-rated health were treated as outcome measures...

  4. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  5. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  6. Sequential Optimization of Paths in Directed Graphs Relative to Different Cost Functions

    KAUST Repository

    Mahayni, Malek A.

    2011-07-01

    Finding optimal paths in directed graphs is a wide area of research that has received much of attention in theoretical computer science due to its importance in many applications (e.g., computer networks and road maps). Many algorithms have been developed to solve the optimal paths problem with different kinds of graphs. An algorithm that solves the problem of paths’ optimization in directed graphs relative to different cost functions is described in [1]. It follows an approach extended from the dynamic programming approach as it solves the problem sequentially and works on directed graphs with positive weights and no loop edges. The aim of this thesis is to implement and evaluate that algorithm to find the optimal paths in directed graphs relative to two different cost functions ( , ). A possible interpretation of a directed graph is a network of roads so the weights for the function represent the length of roads, whereas the weights for the function represent a constraint of the width or weight of a vehicle. The optimization aim for those two functions is to minimize the cost relative to the function and maximize the constraint value associated with the function. This thesis also includes finding and proving the relation between the two different cost functions ( , ). When given a value of one function, we can find the best possible value for the other function. This relation is proven theoretically and also implemented and experimented using Matlab®[2].

  7. Permeable Barrier Materials for Strontium Immobilization: - UFA Determination of Hydraulic Conductivity. - Column Sorption Experiments

    National Research Council Canada - National Science Library

    Moody, T

    1996-01-01

    Selected materials were tested to emulate a permeable barrier and to examine the: (1) capture efficiency of these materials relating to the immobilization of strontium-90 and hexavalent chromium in Hanford groundwater...

  8. Galaxy luminosity function and Tully-Fisher relation: reconciled through rotation-curve studies

    International Nuclear Information System (INIS)

    Cattaneo, Andrea; Salucci, Paolo; Papastergis, Emmanouil

    2014-01-01

    The relation between galaxy luminosity L and halo virial velocity v vir required to fit the galaxy luminosity function differs from the observed Tully-Fisher relation between L and disk speed v rot . Because of this, the problem of reproducing the galaxy luminosity function and the Tully-Fisher relation simultaneously has plagued semianalytic models since their inception. Here we study the relation between v rot and v vir by fitting observational average rotation curves of disk galaxies binned in luminosity. We show that the v rot -v vir relation that we obtain in this way can fully account for this seeming inconsistency. Therefore, the reconciliation of the luminosity function with the Tully-Fisher relation rests on the complex dependence of v rot on v vir , which arises because the ratio of stellar mass to dark matter mass is a strong function of halo mass.

  9. Effects of water activity and low molecular weight humectants on skin permeability and hydration dynamics - a double-blind, randomized and controlled study.

    Science.gov (United States)

    Albèr, C; Buraczewska-Norin, I; Kocherbitov, V; Saleem, S; Lodén, M; Engblom, J

    2014-10-01

    The mammalian skin is a barrier that effectively separates the water-rich interior of the body from the normally dryer exterior. Changes in the external conditions, for example ambient humidity, have been shown to affect the skin barrier properties. The prime objective of this study was to evaluate the effect of water activity of a topical formulation on skin hydration and permeability. A second objective was to gain more understanding on how two commonly used humectants, urea and glycerol, affect skin barrier function in vivo. Simple aqueous formulations were applied under occlusion to the volar forearm of healthy volunteers. Following 4-h exposure, skin water loss (by transepidermal water loss measurements), skin hydration (by Corneometry) and skin permeability (by time to vasodilation due to benzyl nicotinate exposure) were monitored. The results demonstrate that a relatively small change in the water activity of a topical formulation is sufficient to induce considerable effects on stratum corneum hydration and permeability to exogenous substances. Exposing the skin to high water activity leads to increased skin hydration and also increased permeability. Furthermore, urea and glycerol promote skin hydration and permeability even at reduced water activity of the applied formulation. These results highlight the importance of considering the water activity in topically applied formulations and the potential benefit of using humectants. The results may impact formulation optimization in how to facilitate skin hydration and to modify skin permeability by temporarily open and close the skin barrier. © 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  10. Health-Related Quality of Life in Children with High-Functioning Autism

    Science.gov (United States)

    Potvin, Marie-Christine; Snider, Laurie; Prelock, Patricia A.; Wood-Dauphinee, Sharon; Kehayia, Eva

    2015-01-01

    The health-related quality of life of school-aged children with high-functioning autism is poorly understood. The objectives of this study were to compare the health-related quality of life of children with high-functioning autism to that of typically developing peers and to compare child-self and parent-proxy reports of health-related quality of…

  11. Characterization of the mechanical and hydraulic damage in the excavation damaged zone of MHM with gas permeability measurement

    International Nuclear Information System (INIS)

    Yang, D.

    2008-09-01

    water retention curve, the kinetic dehydration, the dehydration shrink and wetting crack in samples were measured and analyzed. The coefficient of hydraulic diffusion determined from the evolution of mass is about 5.10 -10 m 2 .s -1 . The gas permeability (k) under the isotropic stress of 5 MPa increases from 10 -21 to 10 -18 m 2 when the imposed relative humidity decreases from 98 % to 25 %. A quasi-linear relation between log(k) and Saturation has been observed and mathematically formulated. The gas permeability as a function of deviator stress has also been studied and the results confirm that the effect of the deviator is not evident, even when the deviator excesses the damage threshold. These results coincide with Zhang's observations on the same rock of MHM. The deformation and the acoustics velocity of samples have been traced during the tests and the microstructure of mudstone has been studied with the method of mercury intrusion. The factors influencing the measure of gas permeability, such as the Klinkenberg effect, the variation of saturation during the tests, the dissolution of gas in water and the water transformation due to the gas pressure, especially the leak tightness of the testing system, have been discussed in the study. (author)

  12. Borehole stoneley waves and permeability: Laboratory results

    International Nuclear Information System (INIS)

    Winkler, K.W.; Plona, T.J.; Froelich, B.; Liu, H.L.

    1987-01-01

    Recent interest in full waveform sonic logging has created the need for full waveform laboratory experiments on model boreholes. Of particular interest is the investigation of Stoneley waves and their interaction with permeable formations. The authors describe experimental results that show how Stoneley wave slowness and attenuation are affected by formation permeability. Both slowness and attenuation (1/Q) are observed to increase with formation permeability. This increase is frequency dependent, being greatest at low frequencies. The presence of simulated mudcakes on the borehole wall reduces the permeability effect on Stoneley waves, but does not eliminate it. The mudcake effect is frequency dependent, being greatest at low frequencies. In our experiments on rocks, the laboratory data is in qualitative agreement with theoretical predictions. In a very well characterized synthetic porous material, theory and experiment are in good quantitative agreement

  13. Octopus microvasculature: permeability to ferritin and carbon.

    Science.gov (United States)

    Browning, J

    1979-01-01

    The permeability of Octopus microvasculature was investigated by intravascular injection of carbon and ferritin. Vessels were tight to carbon while ferritin penetrated the pericyte junction, and was found extravascularly 1-2 min after its introduction. Vesicles occurred rarely in pericytes; fenestrae were absent. The discontinuous endothelial layer did not consitute a permeability barrier. The basement membrane, although retarding the movement of ferritin, was permeable to it; carbon did not penetrate the basement membrane. Evidence indicated that ferritin, and thus similarly sized and smaller water soluble materials, traverse the pericyte junction as a result of bulk fluid flow. Comparisons are made with the convective (or junctional) and slower, diffusive (or vesicular) passage of materials known to occur across the endothelium of continuous capillaries in mammals. Previous macrophysiological determinations concerning the permeability of Octopus vessels are questioned in view of these findings. Possible reasons for some major structural differences in the microcirculatory systems of cephalopods and vertebrates are briefly discussed.

  14. Dentin Permeability of Carious Primary Teeth

    African Journals Online (AJOL)

    primary dental pulp make it difficult to determine which modality offers the best ... The most common pathology of the dentine is dental caries. ... to evaluate dentine permeability is to calculate its hydraulic conductance (Lp) using fluid filtration ...

  15. Permeability After Impact Testing of Composite Laminates

    Science.gov (United States)

    Nettles, Alan T.

    2003-01-01

    Since composite laminates are beginning to be identified for use in reusable launch vehicle propulsion systems, an understanding of their permeance is needed. A foreign object impact event can cause a localized area of permeability (leakage) in a polymer matrix composite and it is the aim of this study to assess a method of quantifying permeability-after-impact results. A simple test apparatus is presented and variables that could affect the measured values of permeability-after-impact were assessed. Once it was determined that valid numbers were being measured, a fiber/resin system was impacted at various impact levels and the resulting permeability measured, first with a leak check solution (qualitative) then using the new apparatus (quantitative). The results showed that as the impact level increased, so did the measured leakage. As the pressure to the specimen was increased, the leak rate was seen to increase in a non-linear fashion for almost all of the specimens tested.

  16. Characterization of the permeability of the blast furnace lower part

    International Nuclear Information System (INIS)

    Negro, P.; Petit, C.; Urvoy, A.; Sert, D.; Pierret, H.

    2001-01-01

    In the context of high coal injection and high productivity operation, the coke behaviour inside the blast furnace hearth is the main parameter to control. Different and complementary investigations as radioactive and helium tracer injections, liquids and coke samplings, have been carried out at Sollac Fos BF1 using the tuyere probe to determine the hearth permeability and its evolutions as a function of the main control parameters, and to understand the hearth activity. The results of all these experiments give a very consistent picture of a heterogenous hearth with three concentric areas of various permeabilities to gas and liquids. A two concentric zones model has been built, which is in good agreement with the experimental results. It enables to evaluate the impact of the central zone on the liquids flow at the periphery. (author)

  17. Simultaneous search for symmetry-related molecules in cross-rotation functions

    International Nuclear Information System (INIS)

    Yeates, T.O.

    1989-01-01

    In a typical cross-rotation function, the Patterson function of a single search molecule is compared with an observed Patterson function, which contains a set of symmetry-related intramolecular vector sets. In principle, it is better to search for the symmetry-related molecules simultaneously, and Nordman has reported success with an algorithm of this type. In this paper, the differences between the ordinary search and a simultaneous search are investigated, and it is shown that the combined presence of crystallographic symmetry and approximate symmetry of a search model may lead to significant bias in conventional rotation functions. The nature and magnitude of this symmetry bias are discussed. An efficient algorithm is derived for generating a modified unbiased cross-rotation function map from conventional rotation functions. Two examples are described that demonstrate improvement in the quality of the rotation function maps and the ability to obtain physically meaningful correlation coefficients. (orig.)

  18. Changes in social relations in old age. Are they influenced by functional ability?

    DEFF Research Database (Denmark)

    Avlund, Kirsten; Due, Pernille; Holstein, Bjørn Evald

    2002-01-01

    The aims of this article were to describe changes in social relations from ages 75 to 80, and analyze whether changes in social relations are influenced by functional ability at age 75. The study includes data from the NORA follow-up study of 75-80 year-old men and women in Jyväskylä (Finland......, close friends, acquaintances, and neighbors; 2) diversity of social relations (number of types of social contacts); 3) telephone contacts; and 4) social participation. The function of social relations was measured by instrumental social support. Functional ability was measured by tiredness and need......), Göteborg (Sweden) and Glostrup (Denmark). The present analyses include the 743 persons who participated in both studies and who answered the questions about social relations. The structure of social relations was measured by: 1) frequency of contacts with children, grand/greatgrandchildren, relatives...

  19. Surface sedimentation at permeable pavement systems

    DEFF Research Database (Denmark)

    Støvring, Jan; Dam, Torben; Jensen, Marina Bergen

    2018-01-01

    Newly installed permeable pavement (PP) systems provide high surface infiltration capacity, but the accumulation of sediments causes a decrease in capacity over time, eventually leading to surface clogging. With the aim of investigating local sedimentation processes and the importance of restorat......Newly installed permeable pavement (PP) systems provide high surface infiltration capacity, but the accumulation of sediments causes a decrease in capacity over time, eventually leading to surface clogging. With the aim of investigating local sedimentation processes and the importance...

  20. Permeability and stress-jump effects on magnetic drug targeting in a permeable microvessel using Darcy model

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, S., E-mail: sachinshaw@gmail.com [Department of Mathematics and Statistical Sciences, Botswana International University of Science and Technology, Private Bag 16, Palapye (Botswana); Sutradhar, A.; Murthy, PVSN [Department of Mathematics, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal (India)

    2017-05-01

    In the present paper, we investigated the influence of permeability of the carrier particle and stress jump condition on the porous spherical surface in magnetic drug targeting through a permeable microvessel. The nature of blood is defined by non-Newtonian Casson fluid in the core region of the microvessel and Newtonian fluid in the peripheral region which is located near the surface of the wall of the microvessel. The magnetic particles are considered as spherical and in nanosize, embedded in the carrier particle along with drug particles. A magnet is placed near the tumor position to generate a magnetic field. The relative motion of the carrier particle is the resultant of the fluidic force, magnetic force and Saffman drag force which are calculated for the spherical carrier particle. Trajectories of the carrier particle along the radial and axial direction are calculated. Effect of different parameters such as stress-jump constant, permeability of the carrier particle, pressure gradient, yield stress, Saffman force, volume fraction of the embedded magnetic nanoparticles, permeability of the microvessel wall, and the radius of the carrier particle on the trajectory of the carrier particle are discussed and displayed graphically. - Highlights: • In the present manuscript, we considered the porous carrier particle which provide a larger surface area contact with the fluid than the solid spherical carrier particle. It shows that the porous carrier particle are captured easily than the solid carrier particle. • Introduce Suffman force on the carrier particle which commences an additional resistance which acts opposite to the surface wall and helps the particles to go away from the tumor position. • Considered stress jump condition at the surface of the porous carrier particle which enhanced the tendency of the carrier particle to be capture near the tumor. • Used Darcy model to define the permeability of the wall of the microvessel.

  1. Relation of intelligence to ego functioning in an adult psychiatric population.

    Science.gov (United States)

    Allen, J G; Coyne, L; David, E

    1986-01-01

    Wechsler Adult Intelligence Scale-Revised (WAIS-R) IQs and clinical ratings of 10 ego functions in a diagnostically heterogeneous sample of 60 adult psychiatric inpatients were correlated. With severity of pathology statistically controlled, higher intelligence was associated with more adequate ego functioning in several spheres: primary autonomous functions, thought processes, object relations, and mastery-competence. There were also some clinically meaningful differences between the Verbal and Performance IQs in the pattern of correlations. Extending Hartmann's original views, the authors employ an ethological framework to conceptualize intelligence in relation to the ego's role in adaptation, emphasizing that intelligence is an important-albeit neglected-aspect of ego functioning.

  2. Recurrent formulas and some exact relations for radial integrals with Dirac and Schroedinger wave functions

    International Nuclear Information System (INIS)

    Shabaev, V.M.

    1984-01-01

    Some exact relations are derived for radial integrals with Dirac wave functions. These relations are used for calculating radial integrals in the case of the Coulomb field. The threedimensional harmonic oscillator is also considered and exact formulae for the dipole transition probabilities are obtained using general relations between matrix elements

  3. Defining clogging potential for permeable concrete.

    Science.gov (United States)

    Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

    2018-08-15

    Permeable concrete is used to reduce urban flooding as it allows water to flow through normally impermeable infrastructure. It is prone to clogging by particulate matter and predicting the long-term performance of permeable concrete is challenging as there is currently no reliable means of characterising clogging potential. This paper reports on the performance of a range of laboratory-prepared and commercial permeable concretes, close packed glass spheres and aggregate particles of varying size, exposed to different clogging methods to understand this phenomena. New methods were developed to study clogging and define clogging potential. The tests involved applying flowing water containing sand and/or clay in cycles, and measuring the change in permeability. Substantial permeability reductions were observed in all samples, particularly when exposed to sand and clay simultaneously. Three methods were used to define clogging potential based on measuring the initial permeability decay, half-life cycle and number of cycles to full clogging. We show for the first time strong linear correlations between these parameters for a wide range of samples, indicating their use for service-life prediction. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Accurate control testing for clay liner permeability

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, R J

    1991-08-01

    Two series of centrifuge tests were carried out to evaluate the use of centrifuge modelling as a method of accurate control testing of clay liner permeability. The first series used a large 3 m radius geotechnical centrifuge and the second series a small 0.5 m radius machine built specifically for research on clay liners. Two permeability cells were fabricated in order to provide direct data comparisons between the two methods of permeability testing. In both cases, the centrifuge method proved to be effective and efficient, and was found to be free of both the technical difficulties and leakage risks normally associated with laboratory permeability testing of fine grained soils. Two materials were tested, a consolidated kaolin clay having an average permeability coefficient of 1.2{times}10{sup -9} m/s and a compacted illite clay having a permeability coefficient of 2.0{times}10{sup -11} m/s. Four additional tests were carried out to demonstrate that the 0.5 m radius centrifuge could be used for linear performance modelling to evaluate factors such as volumetric water content, compaction method and density, leachate compatibility and other construction effects on liner leakage. The main advantages of centrifuge testing of clay liners are rapid and accurate evaluation of hydraulic properties and realistic stress modelling for performance evaluations. 8 refs., 12 figs., 7 tabs.

  5. Cell permeability beyond the rule of 5.

    Science.gov (United States)

    Matsson, Pär; Doak, Bradley C; Over, Björn; Kihlberg, Jan

    2016-06-01

    Drug discovery for difficult targets that have large and flat binding sites is often better suited to compounds beyond the "rule of 5" (bRo5). However, such compounds carry higher pharmacokinetic risks, such as low solubility and permeability, and increased efflux and metabolism. Interestingly, recent drug approvals and studies suggest that cell permeable and orally bioavailable drugs can be discovered far into bRo5 space. Tactics such as reduction or shielding of polarity by N-methylation, bulky side chains and intramolecular hydrogen bonds may be used to increase cell permeability in this space, but often results in decreased solubility. Conformationally flexible compounds can, however, combine high permeability and solubility, properties that are keys for cell permeability and intestinal absorption. Recent developments in computational conformational analysis will aid design of such compounds and hence prediction of cell permeability. Transporter mediated efflux occurs for most investigated drugs in bRo5 space, however it is commonly overcome by high local intestinal concentrations on oral administration. In contrast, there is little data to support significant impact of transporter-mediated intestinal absorption in bRo5 space. Current knowledge of compound properties that govern transporter effects of bRo5 drugs is limited and requires further fundamental and comprehensive studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Aberrant development of functional connectivity among resting state-related functional networks in medication-naïve ADHD children.

    Directory of Open Access Journals (Sweden)

    Jeewook Choi

    Full Text Available OBJECTIVE: The aim of this study was to investigate the compromised developmental trajectory of the functional connectivity among resting-state-related functional networks (RSFNs in medication-naïve children with attention-deficit/hyperactivity disorder (ADHD. SUBJECTS AND METHODS: Using both independent component analysis and dual regression, subject-specific time courses of 12 RSFNs were extracted from both 20 medication-naïve children with ADHD, and 20 age and gender-matched control children showing typical development (TDC. Both partial correlation coefficients among the 12 RSFNs and a resting-state resource allocation index (rsRAI of the salience network (SN were entered into multiple linear regression analysis to investigate the compromised, age-related change in medication-naïve ADHD children. Finally, correlation analyses were performed between the compromised RSFN connections showing significant group-by-age interaction and rsRAI of SN or clinical variables. RESULTS: Medication-naïve ADHD subjects failed to show age-related increment of functional connectivity in both rsRAI of SN and two RSFN connections, SN-Sensory/motor and posterior default mode/precuneus network (pDMN/prec--anterior DMN. Lower SN-Sensory/motor connectivity was related with higher scores on the ADHD Rating Scale, and with poor scores on the continuous performance test. The pDMN/prec-aDMN connectivity was positively related with rsRAI of SN. CONCLUSIONS: Our results suggest that medication-naïve ADHD subjects may have delayed maturation of the two functional connections, SN-Sensory/Motor and aDMN-pDMN/prec. Interventions that enhance the functional connectivity of these two connections may merit attention as potential therapeutic or preventive options in both ADHD and TDC.

  7. Clearance of technetium-99m-labeled DTPA in hyperthyroidism without clinical evidence of lung disease, and relation to pulmonary function

    International Nuclear Information System (INIS)

    Guldiken, S.; Tugrul, A.; Altiay, G.; Hacimahmutoglu, S.; Durmus-Altun, G.

    2005-01-01

    The mechanisms of dyspnea and exercise intolerance have not been fully elucidated. We aimed to investigate the clearance rate of technetium-99m diethyltriaminepentaaceticacid (Tc-99m DTPA) from lungs in hyperthyroid patients without clinical evidence of lung disease and to explore the interactions between their Tc-99m DTPA radioaerosol lung scintigraphy, spirometric measurements, and the levels of thyroid hormones. We studied 19 hyperthyroid patients and 16 sex- and age-matched controls. Thyroid hormone levels were assessed. Spirometric lung function tests, diffusing capacity of the lung for carbon monoxide (DLCO) and the clearance rate of Tc-99m DTPA were performed in all participants. Ratio of DLCO value to the alveolar ventilation (DLCO/VA) and the means of half-time (T 1/2 ) of Tc-99m DTPA clearance rate, which were used to evaluate alveolar-capillary membrane permeability, were calculated. There were no statistical differences between spirometric parameters (vital capacity (VC), force vital capacity (FVC), one second forced expiratory volume (FEV 1 )/FVC, mean forced expiratory flow during the middle of FVC (FEF 25-75)) of the two groups (p>0.05). Although the mean FEV 1 level was significantly lower in the hyperthyroid patients than the control subjects (p 1 was only less than 80 percent of the predicted value. No significant difference in the means of DLCO, DLCO/VA or T 1/2 values of Tc-99m DTPA clearance was observed between the two groups (p>0.05). In hyperthyroid patients, there was a positive relation between DLCO/VA, DLCO/VA% and T 1/2 values of Tc-99m DTPA clearance (p 1/2 values of Tc-99m DTPA clearance in hyperthyroid group (p>0.05). We conclude that increased thyroid hormones have no effect on permeability of alveolar-capillary membrane in hyperthyroid patients. (author)

  8. Permeability of sediment cores from methane hydrate deposit in the Eastern Nankai Trough, Japan

    Science.gov (United States)

    Konno, Y.; Yoneda, J.; Egawa, K.; Ito, T.; Jin, Y.; Kida, M.; Suzuki, K.; Nakatsuka, Y.; Nagao, J.

    2013-12-01

    Effective and absolute permeability are key parameters for gas production from methane-hydrate-bearing sandy sediments. Effective and/or absolute permeability have been measured using methane-hydrate-bearing sandy cores and clayey and silty cores recovered from Daini Atsumi Knoll in the Eastern Nankai Trough during the 2012 JOGMEC/JAPEX Pressure coring operation. Liquid-nitrogen-immersed cores were prepared by rapid depressurization of pressure cores recovered by a pressure coring system referred to as the Hybrid PCS. Cores were shaped cylindrically on a lathe with spraying of liquid nitrogen to prevent hydrate dissociation. Permeability was measured by a flooding test or a pressure relaxation method under near in-situ pressure and temperature conditions. Measured effective permeability of hydrate-bearing sediments is less than tens of md, which are order of magnitude less than absolute permeability. Absolute permeability of clayey cores is approximately tens of μd, which would perform a sealing function as cap rocks. Permeability reduction due to a swelling effect was observed for a silty core during flooding test of pure water mimicking hydrate-dissociation-water. Swelling effect may cause production formation damage especially at a later stage of gas production from methane hydrate deposits. This study was financially supported by the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) that carries out Japan's Methane Hydrate R&D Program conducted by the Ministry of Economy, Trade and Industry (METI).

  9. Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods.

    Science.gov (United States)

    Li, Hui; Kayhanian, Masoud; Harvey, John T

    2013-03-30

    Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Spatial Assessment of Forest Ecosystem Functions and Services using Human Relating Factors for SDG

    Science.gov (United States)

    Song, C.; Lee, W. K.; Jeon, S. W.; Kim, T.; Lim, C. H.

    2015-12-01

    Application of ecosystem service concept in environmental related decision making could be numerical and objective standard for policy maker between preserving and developing perspective of environment. However, pursuing maximum benefit from natural capital through ecosystem services caused failure by losing ecosystem functions through its trade-offs. Therefore, difference between ecosystem functions and services were demonstrated and would apply human relating perspectives. Assessment results of ecosystem functions and services can be divided 3 parts. Tree growth per year set as the ecosystem function factor and indicated through so called pure function map. After that, relating functions can be driven such as water conservation, air pollutant purification, climate change regulation, and timber production. Overall process and amount are numerically quantified. These functional results can be transferred to ecosystem services by multiplying economic unit value, so function reflecting service maps can be generated. On the other hand, above services, to implement more reliable human demand, human reflecting service maps are also be developed. As the validation, quantified ecosystem functions are compared with former results through pixel based analysis. Three maps are compared, and through comparing difference between ecosystem function and services and inversed trends in function based and human based service are analysed. In this study, we could find differences in PF, FRS, and HRS in relation to based ecosystem conditions. This study suggests that the differences in PF, FRS, and HRS should be understood in the decision making process for sustainable management of ecosystem services. Although the analysis is based on in sort existing process separation, it is important to consider the possibility of different usage of ecosystem function assessment results and ecosystem service assessment results in SDG policy making. Furthermore, process based functional approach

  11. The Development of Metaphor Comprehension and Its Relationship with Relational Verbal Reasoning and Executive Function.

    Directory of Open Access Journals (Sweden)

    Nuria Carriedo

    Full Text Available Our main objective was to analyse the different contributions of relational verbal reasoning (analogical and class inclusion and executive functioning to metaphor comprehension across development. We postulated that both relational reasoning and executive functioning should predict individual and developmental differences. However, executive functioning would become increasingly involved when metaphor comprehension is highly demanding, either because of the metaphors' high difficulty (relatively novel metaphors in the absence of a context or because of the individual's special processing difficulties, such as low levels of reading experience or low semantic knowledge. Three groups of participants, 11-year-olds, 15-year-olds and young adults, were assessed in different relational verbal reasoning tasks-analogical and class-inclusion-and in executive functioning tasks-updating information in working memory, inhibition, and shifting. The results revealed clear progress in metaphor comprehension between ages 11 and 15 and between ages 15 and 21. However, the importance of executive function in metaphor comprehension was evident by age 15 and was restricted to updating information in working memory and cognitive inhibition. Participants seemed to use two different strategies to interpret metaphors: relational verbal reasoning and executive functioning. This was clearly shown when comparing the performance of the "more efficient" participants in metaphor interpretation with that of the "less efficient" ones. Whereas in the first case none of the executive variables or those associated with relational verbal reasoning were significantly related to metaphor comprehension, in the latter case, both groups of variables had a clear predictor effect.

  12. The Development of Metaphor Comprehension and Its Relationship with Relational Verbal Reasoning and Executive Function.

    Science.gov (United States)

    Carriedo, Nuria; Corral, Antonio; Montoro, Pedro R; Herrero, Laura; Ballestrino, Patricia; Sebastián, Iraia

    2016-01-01

    Our main objective was to analyse the different contributions of relational verbal reasoning (analogical and class inclusion) and executive functioning to metaphor comprehension across development. We postulated that both relational reasoning and executive functioning should predict individual and developmental differences. However, executive functioning would become increasingly involved when metaphor comprehension is highly demanding, either because of the metaphors' high difficulty (relatively novel metaphors in the absence of a context) or because of the individual's special processing difficulties, such as low levels of reading experience or low semantic knowledge. Three groups of participants, 11-year-olds, 15-year-olds and young adults, were assessed in different relational verbal reasoning tasks-analogical and class-inclusion-and in executive functioning tasks-updating information in working memory, inhibition, and shifting. The results revealed clear progress in metaphor comprehension between ages 11 and 15 and between ages 15 and 21. However, the importance of executive function in metaphor comprehension was evident by age 15 and was restricted to updating information in working memory and cognitive inhibition. Participants seemed to use two different strategies to interpret metaphors: relational verbal reasoning and executive functioning. This was clearly shown when comparing the performance of the "more efficient" participants in metaphor interpretation with that of the "less efficient" ones. Whereas in the first case none of the executive variables or those associated with relational verbal reasoning were significantly related to metaphor comprehension, in the latter case, both groups of variables had a clear predictor effect.

  13. Relation between equal-time and light-front wave functions

    International Nuclear Information System (INIS)

    Miller, Gerald A.; Tiburzi, Brian C.

    2010-01-01

    The relation between equal-time and light-front wave functions is studied using models for which the four-dimensional solution of the Bethe-Salpeter wave function can be obtained. The popular prescription of defining the longitudinal momentum fraction using the instant-form free kinetic energy and third component of momentum is found to be incorrect except in the nonrelativistic limit. One may obtain light-front wave functions from rest-frame, instant-form wave functions by boosting the latter wave functions to the infinite momentum frame. Despite this difficulty, we prove a relation between certain integrals of the equal-time and light-front wave functions.

  14. Sequential Optimization of Paths in Directed Graphs Relative to Different Cost Functions

    KAUST Repository

    Mahayni, Malek A.

    2011-01-01

    developed to solve the optimal paths problem with different kinds of graphs. An algorithm that solves the problem of paths’ optimization in directed graphs relative to different cost functions is described in [1]. It follows an approach extended from

  15. Genome 3D-architecture: Its plasticity in relation to function

    Indian Academy of Sciences (India)

    Kundan Sengupta

    Mini-Review. Genome 3D-architecture: Its plasticity in relation to function. KUNDAN ... MS received 23 October 2017; accepted 14 February 2018; published online 7 April 2018 .... moter Communication and T Cell Fate. Cell 171 103–119.

  16. Ionization Potentials of Chemical Warfare Agents and Related Compounds Determined with Density Functional Theory

    National Research Council Canada - National Science Library

    Wright, J

    2000-01-01

    ...) agents at contaminated sites. Reported herein are theoretical ionization potentials for CW agents and their related compounds calculated using density functional theory at the B3LYP/6-311+G(2d,p) level of theory...

  17. Sequential Optimization of Paths in Directed Graphs Relative to Different Cost Functions

    KAUST Repository

    Abubeker, Jewahir Ali; Chikalov, Igor; Hussain, Shahid; Moshkov, Mikhail

    2011-01-01

    This paper is devoted to the consideration of an algorithm for sequential optimization of paths in directed graphs relative to di_erent cost functions. The considered algorithm is based on an extension of dynamic programming which allows

  18. Suppression of electron waves in relation to the deformation of the electron beam distribution function

    International Nuclear Information System (INIS)

    Fukumasa, O.; Itatani, R.

    1978-01-01

    The change of the electron beam distribution function due to the wave excited by the beam density modulation is observed, in relation to the suppression of electron waves in a beam-plasma system. (Auth.)

  19. AB62. Age-related differences of erectile function in erectile dysfunction patients

    OpenAIRE

    Zhang, Kai; Jiang, Hui; Wang, Xiaofeng

    2014-01-01

    Objectives To investigate the age-related differences of erectile function and erectile hardness in erectile dysfunction (ED) patients. Methods The data is retrieved in the baseline database of a study on ED management which was performed in 46 urological clinics in China. The patients are stratified on the basis of every 10 years (yrs) old. The evaluation questionnaires of ED are the erectile function domain of the International Index of Erectile Function (IIEF-EF) and the Erection Hardness ...

  20. Sleep quality and duration are related to microvascular function: the Amsterdam Growth and Health Longitudinal Study

    NARCIS (Netherlands)

    Bonsen, T.; Wijnstok, N.J.; Hoekstra, T.; Eringa, E.C.; Serne, E.H.; Smulders, Y.M.; Twisk, J.W.R.

    2015-01-01

    Sleep and sleep disorders are related to cardiovascular disease, and microvascular function is an early cardiovascular disease marker. Therefore, the relationship of sleep (measured in sleep quality and duration) with microvascular function was examined in healthy adults. Sleep quality was assessed

  1. Executive Functioning in Children, and Its Relations with Reasoning, Reading, and Arithmetic

    Science.gov (United States)

    van der Sluis, Sophie; de Jong, Peter F.; van der Leij, Aryan

    2007-01-01

    The aims of this study were to investigate whether the executive functions, inhibition, shifting, and updating, are distinguishable as latent variables (common factors) in children aged 9 to 12, and to examine the relations between these executive functions and reading, arithmetic, and (non)verbal reasoning. Confirmatory factor analysis was used…

  2. A spatial compression technique for head-related transfer function interpolation and complexity estimation

    DEFF Research Database (Denmark)

    Shekarchi, Sayedali; Christensen-Dalsgaard, Jakob; Hallam, John

    2015-01-01

    A head-related transfer function (HRTF) model employing Legendre polynomials (LPs) is evaluated as an HRTF spatial complexity indicator and interpolation technique in the azimuth plane. LPs are a set of orthogonal functions derived on the sphere which can be used to compress an HRTF dataset...

  3. Effect of Taichi Softball on Function-Related Outcomes in Older Adults: A Randomized Control Trial

    Directory of Open Access Journals (Sweden)

    Lin Lou

    2017-01-01

    Full Text Available The purpose of this present study was to examine the effect of Taichi softball (TCSB on physical function in Chinese older adults. Eighty Chinese older adults were randomly assigned into either an experimental group experiencing four 90-minute TCSB sessions weekly for seven consecutive weeks or a control group. At baseline and 7 weeks later, all participants were asked to perform physical functional tests for both lower and upper limbs. Multiple separate Analyses of Variance (ANOVA with repeated measures were applied to evaluate the effects of TCSB on function-related outcomes between baseline and postintervention in the two groups. The findings indicate that a short-term and intensive TCSB training program does not only improve low limb-related physical function such as dynamic balance and leg strength, but also strengthen upper limb-related physical function (e.g., arm and forearm strength, shoulder mobility, fine motor control, handgrip strength, and fine motor function. Health professionals could take into account TCSB exercise as an alternative method to help maintain or alleviate the inevitable age-related physical function degeneration in healthy older adults. In addition, researchers could investigate the effect of TCSB exercise on physical function in special populations such as patients with different chronic diseases or neurological disorder (e.g., Parkinson’s disease.

  4. Relative work function of clean molybdenum single-crystal planes determined by field emission microscopy

    International Nuclear Information System (INIS)

    Bergeret, G.; Abon, M.; Tardy, B.; Teichner, S.J.

    1974-01-01

    A probe-hole field emission microscope was used to determine the work function of clean molybdenum single crystal planes relative to the average work function of the field emitter, assumed to be 4.20 eV. Results are compared with other available data

  5. Racism-Related Stress, General Life Stress, and Psychological Functioning among Black American Women

    Science.gov (United States)

    Pieterse, Alex L.; Carter, Robert T.; Ray, Kilynda V.

    2013-01-01

    The relationship between general life stress, perceived racism, and psychological functioning was explored in a sample of 118 Black American women. Findings indicate that racism-related stress was not a significant predictor of psychological functioning when controlling for general life stress. Perceived racism was positively associated with…

  6. Recurrence Relations and Generating Functions of the Sequence of Sums of Corresponding Factorials and Triangular Numbers

    Directory of Open Access Journals (Sweden)

    Romer C. Castillo

    2015-11-01

    Full Text Available This study established some recurrence relations and exponential generating functions of the sequence of factoriangular numbers. A factoriangular number is defined as a sum of corresponding factorial and triangular number. The proofs utilize algebraic manipulations with some known results from calculus, particularly on power series and Maclaurin’s series. The recurrence relations were found by manipulating the formula defining a factoringular number while the ascertained exponential generating functions were in the closed form.

  7. Green's functions and trace formulas for generalized Sturm-Liouville problems related by Darboux transformations

    International Nuclear Information System (INIS)

    Schulze-Halberg, Axel

    2010-01-01

    We study Green's functions of the generalized Sturm-Liouville problems that are related to each other by Darboux -equivalently, supersymmetrical - transformations. We establish an explicit relation between the corresponding Green's functions and derive a simple formula for their trace. The class of equations considered here includes the conventional Schroedinger equation and generalizations, such as for position-dependent mass and with linearly energy-dependent potential, as well as the stationary Fokker-Planck equation.

  8. Experimental drying shrinkage of hardened cement pastes as a function of relative humidity

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Baroghel, V.B.

    1996-01-01

    The results of an experimental study concerning drying shrinkage measured as a function of relative humidity on thin specimens of mature hardened cement pastes are presented. The results obtained at two laboratories are compared.......The results of an experimental study concerning drying shrinkage measured as a function of relative humidity on thin specimens of mature hardened cement pastes are presented. The results obtained at two laboratories are compared....

  9. Sequential optimization of matrix chain multiplication relative to different cost functions

    KAUST Repository

    Chikalov, Igor; Hussain, Shahid; Moshkov, Mikhail

    2011-01-01

    In this paper, we present a methodology to optimize matrix chain multiplication sequentially relative to different cost functions such as total number of scalar multiplications, communication overhead in a multiprocessor environment, etc. For n matrices our optimization procedure requires O(n 3) arithmetic operations per one cost function. This work is done in the framework of a dynamic programming extension that allows sequential optimization relative to different criteria. © 2011 Springer-Verlag Berlin Heidelberg.

  10. Health-related quality of life in children with high-functioning autism.

    Science.gov (United States)

    Potvin, Marie-Christine; Snider, Laurie; Prelock, Patricia A; Wood-Dauphinee, Sharon; Kehayia, Eva

    2015-01-01

    The health-related quality of life of school-aged children with high-functioning autism is poorly understood. The objectives of this study were to compare the health-related quality of life of children with high-functioning autism to that of typically developing peers and to compare child-self and parent-proxy reports of health-related quality of life of children. A cross-sectional study of children with high-functioning autism (n = 30) and peers (n = 31) was conducted using the Pediatric Quality of Life Inventory 4.0 Generic Core Scales. Children with high-functioning autism had significantly poorer health-related quality of life than peers whether reported by themselves (p children and parental scores suggested variance in points of view. This study specifically investigated health-related quality of life in children with high-functioning autism as compared to a sample of peers, from the child's perspective. It strengthens earlier findings that children with high-functioning autism experience poorer health-related quality of life than those without this disorder and points to the importance of clinicians working with families to identify areas in a child's life that promote or hinder their sense of well-being. © The Author(s) 2013.

  11. The solubility-permeability interplay and oral drug formulation design: Two heads are better than one.

    Science.gov (United States)

    Dahan, Arik; Beig, Avital; Lindley, David; Miller, Jonathan M

    2016-06-01

    Poor aqueous solubility is a major challenge in today's biopharmaceutics. While solubility-enabling formulations can significantly increase the apparent solubility of the drug, the concomitant effect on the drug's apparent permeability has been largely overlooked. The mathematical equation to describe the membrane permeability of a drug comprises the membrane/aqueous partition coefficient, which in turn is dependent on the drug's apparent solubility in the GI milieu, suggesting that the solubility and the permeability are closely related, exhibit a certain interplay between them, and treating the one irrespectively of the other may be insufficient. In this article, an overview of this solubility-permeability interplay is provided, and the available data is analyzed in the context of the effort to maximize the overall drug exposure. Overall, depending on the type of solubility-permeability interplay, the permeability may decrease, remain unchanged, and even increase, in a way that may critically affect the formulation capability to improve the overall absorption. Therefore, an intelligent design of solubility-enabling formulation needs to consider both the solubility afforded by the formulation and the permeability in the new luminal environment resulting from the formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Decision trees to characterise the roles of permeability and solubility on the prediction of oral absorption.

    Science.gov (United States)

    Newby, Danielle; Freitas, Alex A; Ghafourian, Taravat

    2015-01-27

    Oral absorption of compounds depends on many physiological, physiochemical and formulation factors. Two important properties that govern oral absorption are in vitro permeability and solubility, which are commonly used as indicators of human intestinal absorption. Despite this, the nature and exact characteristics of the relationship between these parameters are not well understood. In this study a large dataset of human intestinal absorption was collated along with in vitro permeability, aqueous solubility, melting point, and maximum dose for the same compounds. The dataset allowed a permeability threshold to be established objectively to predict high or low intestinal absorption. Using this permeability threshold, classification decision trees incorporating a solubility-related parameter such as experimental or predicted solubility, or the melting point based absorption potential (MPbAP), along with structural molecular descriptors were developed and validated to predict oral absorption class. The decision trees were able to determine the individual roles of permeability and solubility in oral absorption process. Poorly permeable compounds with high solubility show low intestinal absorption, whereas poorly water soluble compounds with high or low permeability may have high intestinal absorption provided that they have certain molecular characteristics such as a small polar surface or specific topology. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  13. Field-scale permeability and temperature of volcanic crust from borehole data: Campi Flegrei, southern Italy

    Science.gov (United States)

    Carlino, Stefano; Piochi, Monica; Tramelli, Anna; Mormone, Angela; Montanaro, Cristian; Scheu, Bettina; Klaus, Mayer

    2018-05-01

    We report combined measurements of petrophysical and geophysical parameters for a 501-m deep borehole located on the eastern side of the active Campi Flegrei caldera (Southern Italy), namely (i) in situ permeability by pumping tests, (ii) laboratory-determined permeability of the drill core, and (iii) thermal gradients by distributed fiber optic and thermocouple sensors. The borehole was drilled during the Campi Flegrei Deep Drilling Project (in the framework of the International Continental Scientific Drilling Program) and gives information on the least explored caldera sector down to pre-caldera deposits. The results allow comparative assessment of permeability obtained from both borehole (at depth between 422 a 501 m) and laboratory tests (on a core sampled at the same depth) for permeability values of 10-13 m2 (borehole test) and 10-15 m2 (laboratory test) confirm the scale-dependency of permeability at this site. Additional geochemical and petrophysical determinations (porosity, density, chemistry, mineralogy and texture), together with gas flow measurements, corroborate the hypothesis that discrepancies in the permeability values are likely related to in-situ fracturing. The continuous distributed temperature profile points to a thermal gradient of about 200 °C km-1. Our findings (i) indicate that scale-dependency of permeability has to be carefully considered in modelling of the hydrothermal system at Campi Flegrei, and (ii) improve the understanding of caldera dynamics for monitoring and mitigation of this very high volcanic risk area.

  14. Permeability Estimation of Rock Reservoir Based on PCA and Elman Neural Networks

    Science.gov (United States)

    Shi, Ying; Jian, Shaoyong

    2018-03-01

    an intelligent method which based on fuzzy neural networks with PCA algorithm, is proposed to estimate the permeability of rock reservoir. First, the dimensionality reduction process is utilized for these parameters by principal component analysis method. Further, the mapping relationship between rock slice characteristic parameters and permeability had been found through fuzzy neural networks. The estimation validity and reliability for this method were tested with practical data from Yan’an region in Ordos Basin. The result showed that the average relative errors of permeability estimation for this method is 6.25%, and this method had the better convergence speed and more accuracy than other. Therefore, by using the cheap rock slice related information, the permeability of rock reservoir can be estimated efficiently and accurately, and it is of high reliability, practicability and application prospect.

  15. The early development of executive function and its relation to social interaction: A brief review

    Directory of Open Access Journals (Sweden)

    Yusuke eMoriguchi

    2014-04-01

    Full Text Available Executive function (EF refers to the ability to execute appropriate actions and to inhibit inappropriate actions for the attainment of a specific goal. Research has shown that this ability develops rapidly during the preschool years. Recently, it has been proposed that research on executive function should consider the importance of social interaction. In this article, recent evidence regarding the early development of executive function and its relation to social interaction has been reviewed. Research consistently showed that social interaction can influence executive function skills in young children. However, the development of executive function may facilitate the cognitive skills that are important for social interaction. Taken together, there might be functional dependency between the development of executive function and social interaction.

  16. Infinite Relational Modeling of Functional Connectivity in Resting State fMRI

    DEFF Research Database (Denmark)

    Mørup, Morten; Madsen, Kristoffer H.; Dogonowski, Anne Marie

    2010-01-01

    Functional magnetic resonance imaging (fMRI) can be applied to study the functional connectivity of the neural elements which form complex network at a whole brain level. Most analyses of functional resting state networks (RSN) have been based on the analysis of correlation between the temporal...... dynamics of various regions of the brain. While these models can identify coherently behaving groups in terms of correlation they give little insight into how these groups interact. In this paper we take a different view on the analysis of functional resting state networks. Starting from the definition...... of resting state as functional coherent groups we search for functional units of the brain that communicate with other parts of the brain in a coherent manner as measured by mutual information. We use the infinite relational model (IRM) to quantify functional coherent groups of resting state networks...

  17. Knockout of MIMP protein in lactobacillus plantarum lost its regulation of intestinal permeability on NCM460 epithelial cells through the zonulin pathway.

    Science.gov (United States)

    Liu, Zhihua; Kang, Liang; Li, Chao; Tong, Chao; Huang, Meijin; Zhang, Xingwei; Huang, Nanqi; Moyer, Mary Pat; Qin, Huanlong; Wang, Jianping

    2014-10-03

    Previous studies indicated that the micro integral membrane protein located within the media place of the integral membrane protein of Lactobacillus plantarum CGMCC 1258 had protective effects against the intestinal epithelial injury. In our study, we mean to establish micro integral membrane protein -knockout Lactobacillus plantarum (LPKM) to investigate the change of its protective effects and verify the role of micro integral membrane protein on protection of normal intestinal barrier function. Binding assay and intestinal permeability were performed to verify the protective effects of micro integral membrane protein on intestinal permeability in vitro and in vivo. Molecular mechanism was also determined as the zonulin pathway. Clinical data were also collected for further verification of relationship between zonulin level and postoperative septicemia. LPKM got decreased inhibition of EPEC adhesion to NCM460 cells. LPKM had lower ability to alleviate the decrease of intestinal permeability induced by enteropathogenic-e.coli, and prevent enteropathogenic-e.coli -induced increase of zonulin expression. Overexpression of zonulin lowered the intestinal permeability regulated by Lactobacillus plantarum. There was a positive correlation between zonulin level and postoperative septicemia. Therefore, micro integral membrane protein could be necessary for the protective effects of Lactobacillus plantarum on intestinal barrier. MIMP might be a positive factor for Lactobacillus plantarum to protect the intestinal epithelial cells from injury, which could be related to the zonulin pathway.

  18. Psychological distress and visual functioning in relation to vision-related disability in older individuals with cataracts.

    Science.gov (United States)

    Walker, J G; Anstey, K J; Lord, S R

    2006-05-01

    To determine whether demographic, health status and psychological functioning measures, in addition to impaired visual acuity, are related to vision-related disability. Participants were 105 individuals (mean age=73.7 years) with cataracts requiring surgery and corrected visual acuity in the better eye of 6/24 to 6/36 were recruited from waiting lists at three public out-patient ophthalmology clinics. Visual disability was measured with the Visual Functioning-14 survey. Visual acuity was assessed using better and worse eye logMAR scores and the Melbourne Edge Test (MET) for edge contrast sensitivity. Data relating to demographic information, depression, anxiety and stress, health care and medication use and numbers of co-morbid conditions were obtained. Principal component analysis revealed four meaningful factors that accounted for 75% of the variance in visual disability: recreational activities, reading and fine work, activities of daily living and driving behaviour. Multiple regression analyses determined that visual acuity variables were the only significant predictors of overall vision-related functioning and difficulties with reading and fine work. For the remaining visual disability domains, non-visual factors were also significant predictors. Difficulties with recreational activities were predicted by stress, as well as worse eye visual acuity, and difficulties with activities of daily living were associated with self-reported health status, age and depression as well as MET contrast scores. Driving behaviour was associated with sex (with fewer women driving), depression, anxiety and stress scores, and MET contrast scores. Vision-related disability is common in older individuals with cataracts. In addition to visual acuity, demographic, psychological and health status factors influence the severity of vision-related disability, affecting recreational activities, activities of daily living and driving.

  19. Transcytosis Involvement in Transport System and Endothelial Permeability of Vascular Leakage during Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Chanettee Chanthick

    2018-02-01

    Full Text Available The major role of endothelial cells is to maintain homeostasis of vascular permeability and to preserve the integrity of vascular vessels to prevent fluid leakage. Properly functioning endothelial cells promote physiological balance and stability for blood circulation and fluid components. A monolayer of endothelial cells has the ability to regulate paracellular and transcellular pathways for transport proteins, solutes, and fluid. In addition to the paracellular pathway, the transcellular pathway is another route of endothelial permeability that mediates vascular permeability under physiologic conditions. The transcellular pathway was found to be associated with an assortment of disease pathogeneses. The clinical manifestation of severe dengue infection in humans is vascular leakage and hemorrhagic diatheses. This review explores and describes the transcellular pathway, which is an alternate route of vascular permeability during dengue infection that corresponds with the pathologic finding of intact tight junction. This pathway may be the route of albumin transport that causes endothelial dysfunction during dengue virus infection.

  20. Lattice Boltzmann simulations of the permeability and capillary adsorption of cement model microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Zalzale, M. [Laboratory of Construction Materials, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); McDonald, P.J., E-mail: p.mcdonald@surrey.ac.uk [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2012-12-15

    The lattice Boltzmann method is used to investigate the permeability of microstructures of cement pastes generated using the numerical models CEMHYD3D (Bentz, 1997) and {mu}IC (Bishnoi and Scrivener, 2009). Results are reported as a function of paste water-to-cement ratio and degree of hydration. The permeability decreases with increasing hydration and decreasing water-to-cement ratio in agreement with experiment. However the permeability is larger than the experimental data recorded using beam bending methods (Vichit-Vadakan and Scherer, 2002). Notwithstanding, the lattice Boltzmann results compare favourably with alternate numerical methods of permeability calculation for cement model microstructures. In addition, we show early results for the liquid/vapour capillary adsorption and desorption isotherms in the same model {mu}IC structures. The broad features of the experimental capillary porosity isotherm are reproduced, although further work is required to adequately parameterise the model.

  1. Analytical solution for vacuum preloading considering the nonlinear distribution of horizontal permeability within the smear zone.

    Directory of Open Access Journals (Sweden)

    Jie Peng

    Full Text Available The vacuum preloading is an effective method which is widely used in ground treatment. In consolidation analysis, the soil around prefabricated vertical drain (PVD is traditionally divided into smear zone and undisturbed zone, both with constant permeability. In reality, the permeability of soil changes continuously within the smear zone. In this study, the horizontal permeability coefficient of soil within the smear zone is described by an exponential function of radial distance. A solution for vacuum preloading consolidation considers the nonlinear distribution of horizontal permeability within the smear zone is presented and compared with previous analytical results as well as a numerical solution, the results show that the presented solution correlates well with the numerical solution, and is more precise than previous analytical solution.

  2. Permeability and elastic properties of cracked glass under pressure

    Science.gov (United States)

    Ougier-Simonin, A.; GuéGuen, Y.; Fortin, J.; Schubnel, A.; Bouyer, F.

    2011-07-01

    Fluid flow in rocks is allowed through networks of cracks and fractures at all scales. In fact, cracks are of high importance in various applications ranging from rock elastic and transport properties to nuclear waste disposal. The present work aims at investigating thermomechanical cracking effects on elastic wave velocities, mechanical strength, and permeability of cracked glass under pressure. We performed the experiments on a triaxial cell at room temperature which allows for independent controls of the confining pressure, the axial stress, and pore pressure. We produced cracks in original borosilicate glass samples with a reproducible method (thermal treatment with a thermal shock of 300°C). The evolution of the elastic and transport properties have been monitored using elastic wave velocity sensors, strain gage, and flow measurements. The results obtained evidence for (1) a crack family with identified average aspect ratio and crack aperture, (2) a very small permeability which decreases as a power (exponential) function of pressure, and depends on (3) the crack aperture cube. We also show that permeability behavior of a cracked elastic brittle solid is reversible and independent of the fluid nature. Two independent methods (permeability and elastic wave velocity measurements) give these consistent results. This study provides data on the mechanical and transport properties of an almost ideal elastic brittle solid in which a crack population has been introduced. Comparisons with similar data on rocks allow for drawing interesting conclusions. Over the timescale of our experiments, our results do not provide any data on stress corrosion, which should be considered in further study.

  3. Functional food awareness and perceptions in relation to information sources in older adults.

    Science.gov (United States)

    Vella, Meagan N; Stratton, Laura M; Sheeshka, Judy; Duncan, Alison M

    2014-05-17

    The functional food industry has experienced innovative and economic expansion, yet research into consumer perceptions of functional foods and their associated health claims is limited. Among consumers, older adults could benefit from functional foods due to age-related issues pertaining to food and health. The purpose of this research was to identify the need for information related to functional foods among older adults (≥60 years old) and to assess awareness and perceptions of health claims on functional food packages. Community-dwelling older adults (n = 200) completed a researcher administered questionnaire designed to collect information about functional foods including current consumption, motivating factors for consumption, perceived need for information, sources of information for functional foods and awareness of health claims. Prevalence of functional food consumption among participants was 93.0%. Increased awareness and knowledge was the most commonly reported factor that would promote functional food consumption (85.5%) and 63.5% of participants wanted more information about functional foods with preferred sources being newspapers/magazines/books (68.5%) and food labels (66.1%). Participants were predominately (93.5%) aware of health claims on functional foods and those with more education were more likely to report being aware of health claims (p = 0.045). Although functional food consumption among older adults in this sample is high, there is a need for further information regarding functional foods. These results inform stakeholders regarding the potential for information to influence functional food acceptance among older adult consumers.

  4. Functional food awareness and perceptions in relation to information sources in older adults

    Science.gov (United States)

    2014-01-01

    Background The functional food industry has experienced innovative and economic expansion, yet research into consumer perceptions of functional foods and their associated health claims is limited. Among consumers, older adults could benefit from functional foods due to age-related issues pertaining to food and health. The purpose of this research was to identify the need for information related to functional foods among older adults (≥60 years old) and to assess awareness and perceptions of health claims on functional food packages. Methods Community-dwelling older adults (n = 200) completed a researcher administered questionnaire designed to collect information about functional foods including current consumption, motivating factors for consumption, perceived need for information, sources of information for functional foods and awareness of health claims. Results Prevalence of functional food consumption among participants was 93.0%. Increased awareness and knowledge was the most commonly reported factor that would promote functional food consumption (85.5%) and 63.5% of participants wanted more information about functional foods with preferred sources being newspapers/magazines/books (68.5%) and food labels (66.1%). Participants were predominately (93.5%) aware of health claims on functional foods and those with more education were more likely to report being aware of health claims (p = 0.045). Conclusions Although functional food consumption among older adults in this sample is high, there is a need for further information regarding functional foods. These results inform stakeholders regarding the potential for information to influence functional food acceptance among older adult consumers. PMID:24886306

  5. Age-related reorganization of functional networks for successful conflict resolution: a combined functional and structural MRI study.

    Science.gov (United States)

    Schulte, Tilman; Müller-Oehring, Eva M; Chanraud, Sandra; Rosenbloom, Margaret J; Pfefferbaum, Adolf; Sullivan, Edith V

    2011-11-01

    Aging has readily observable effects on the ability to resolve conflict between competing stimulus attributes that are likely related to selective structural and functional brain changes. To identify age-related differences in neural circuits subserving conflict processing, we combined structural and functional MRI and a Stroop Match-to-Sample task involving perceptual cueing and repetition to modulate resources in healthy young and older adults. In our Stroop Match-to-Sample task, older adults handled conflict by activating a frontoparietal attention system more than young adults and engaged a visuomotor network more than young adults when processing repetitive conflict and when processing conflict following valid perceptual cueing. By contrast, young adults activated frontal regions more than older adults when processing conflict with perceptual cueing. These differential activation patterns were not correlated with regional gray matter volume despite smaller volumes in older than young adults. Given comparable performance in speed and accuracy of responding between both groups, these data suggest that successful aging is associated with functional reorganization of neural systems to accommodate functionally increasing task demands on perceptual and attentional operations. Copyright © 2009 Elsevier Inc. All rights reserved.

  6. Empirically Defined Patterns of Executive Function Deficits in Schizophrenia and Their Relation to Everyday Functioning: A Person-Centered Approach

    Science.gov (United States)

    Iampietro, Mary; Giovannetti, Tania; Drabick, Deborah A. G.; Kessler, Rachel K.

    2013-01-01

    Executive function (EF) deficits in schizophrenia (SZ) are well documented, although much less is known about patterns of EF deficits and their association to differential impairments in everyday functioning. The present study empirically defined SZ groups based on measures of various EF abilities and then compared these EF groups on everyday action errors. Participants (n=45) completed various subtests from the Delis–Kaplan Executive Function System (D-KEFS) and the Naturalistic Action Test (NAT), a performance-based measure of everyday action that yields scores reflecting total errors and a range of different error types (e.g., omission, perseveration). Results of a latent class analysis revealed three distinct EF groups, characterized by (a) multiple EF deficits, (b) relatively spared EF, and (c) perseverative responding. Follow-up analyses revealed that the classes differed significantly on NAT total errors, total commission errors, and total perseveration errors; the two classes with EF impairment performed comparably on the NAT but performed worse than the class with relatively spared EF. In sum, people with SZ demonstrate variable patterns of EF deficits, and distinct aspects of these EF deficit patterns (i.e., poor mental control abilities) may be associated with everyday functioning capabilities. PMID:23035705

  7. A Limit Relation for Dunkl-Bessel Functions of Type A and B

    Directory of Open Access Journals (Sweden)

    Margit Rösler

    2008-12-01

    Full Text Available We prove a limit relation for the Dunkl-Bessel function of type BN with multiplicity parameters k_1 on the roots ±ei and k_2 on ±e_i±e_j where k_1 tends to infinity and the arguments are suitably scaled. It gives a good approximation in terms of the Dunkl-type Bessel function of type A_{N−1} with multiplicity k_2. For certain values of k_2 an improved estimate is obtained from a corresponding limit relation for Bessel functions on matrix cones.

  8. Complete recovery of renal allograft function after six days of delay following living related transplantation

    International Nuclear Information System (INIS)

    Arogundade, F.A.; Sanusi, A.A.; Badmus, T.A.

    2008-01-01

    Delayed graft function (DGF), a term employed when a newly transplanted organ does not function efficiently is commonly observed following cadaveric renal transplantation but is very rare after living related transplants. We present a 31-year-old female recipient of a related donor kidney (mother) who had DGF following transplantation due to acute tubular necrosis, probably caused by partial allograft arterial thrombosis, which recovered function after 60 days. Appropriate use of allograft biopsy should be encouraged even in resource-limited settings lest the allograft be assumed to have failed irreversibly. (author)

  9. Third invitational well-testing symposium: well testing in low permeability environments

    Energy Technology Data Exchange (ETDEWEB)

    Doe, T.W.; Schwarz, W.J. (eds.)

    1981-03-01

    The testing of low permeability rocks is common to waste disposal, fossil energy resource development, underground excavation, and geothermal energy development. This document includes twenty-six papers and abstracts, divided into the following sessions: opening session, case histories and related phenomena, well test design in low permeability formations, analysis and interpretation of well test data, and instrumentation for well tests. Separate abstracts were prepared for 15 of the 16 papers; the remaining paper has been previously abstracted. (DLC)

  10. Third invitational well-testing symposium: well testing in low permeability environments

    International Nuclear Information System (INIS)

    Doe, T.W.; Schwarz, W.J.

    1981-03-01

    The testing of low permeability rocks is common to waste disposal, fossil energy resource development, underground excavation, and geothermal energy development. This document includes twenty-six papers and abstracts, divided into the following sessions: opening session, case histories and related phenomena, well test design in low permeability formations, analysis and interpretation of well test data, and instrumentation for well tests. Separate abstracts were prepared for 15 of the 16 papers; the remaining paper has been previously abstracted

  11. Effect of desensitizing agents on dentin permeability.

    Science.gov (United States)

    Ishihata, Hiroshi; Kanehira, Masafumi; Nagai, Tomoko; Finger, Werner J; Shimauchi, Hidetoshi; Komatsu, Masashi

    2009-06-01

    To investigate the in vitro efficacy of two dentin desensitizing products at reducing liquid permeability through human dentin discs. The tested hypothesis was that the products, in spite of different chemical mechanisms were not different at reducing or eliminating flow through dentin discs. Dentin slices (1 mm thick) were prepared from 16 extracted human third molars and their permeability was indirectly recorded in a split chamber model, using a chemiluminescence technique, after EDTA treatment (control), after soaking with albumin, and after desensitizer application. Two products were studied: MS Coat, a self-curing resin-containing oxalate product, and Gluma Desensitizer, a glutaraldehyde/HEMA-based agent without initiator. The dentin slices were mounted between an upper chamber, filled with an aqueous solution of 1% potassium ferricyanide and 0.3% hydrogen peroxide, and a lower chamber filled with 1% sodium hydroxide solution and 0.02% luminol. The upper solution was pressurized, and upon contact with the luminol solution a photochemical signal was generated and recorded as a measure of permeability throughout two consecutive pressurizing cycles at 2.5 and 13 kPa (26 and 133 cm H2O), respectively. The permeability of the control and albumin-soaked samples was similarly high. After application of the desensitizing agents, dentin permeability was reduced to virtually zero at both pressure levels (P < 0.001).

  12. In vivo human buccal permeability of nicotine

    DEFF Research Database (Denmark)

    Adrian, Charlotte L; Olin, Helle B D; Dalhoff, Kim

    2006-01-01

    The aim was to examine the in vivo buccal pH-dependent permeability of nicotine in humans and furthermore compare the in vivo permeability of nicotine to previous in vitro permeability data. The buccal permeability of nicotine was examined in a three-way cross-over study in eight healthy non......-smokers using a buccal perfusion cell. The disappearance of nicotine from perfusion solutions with pH 6.0, 7.4, and 8.1 was studied for 3h. The apparent permeability of nicotine (P(app)) was determined at each pH value. Parotid saliva was collected in an attempt to assess systemic levels of nicotine....... The disappearance rate of nicotine increased significantly as the pH increased, which resulted in P(app) values of 0.57+/-0.55 x 10(-4), 2.10+/-0.23 x 10(-4), and 3.96+/-0.54 x 10(-4)cms(-1) (mean+/-S.D.) at pH 6.0, 7.4, and 8.1, respectively. A linear relationship (R(2)=0.993) was obtained between the P...

  13. Assessment of relative individual renal function based on DMSA uptake corrected for renal size

    International Nuclear Information System (INIS)

    Estorch, M.; Camacho, V.; Tembl, A.; Mena, I.; Hernandez, A.; Flotats, A.; Carrio, I.; Torres, G.; Prat, L.

    2002-01-01

    Decreased relative renal DMSA uptake can be a consequence of abnormal kidney size, associated with normal or impaired renal function. The quantification of relative renal function based on DMSA uptake in both kidneys is an established method for the assessment of individual renal function. Aim: To assess relative renal function by means of quantification of renal DMSA uptake corrected for kidney size. Results were compared with relative renal DMSA uptake without size correction, and were validated against the absolute renal DMSA uptake. Material and Methods: Four-hundred-forty-four consecutive patients (147 adults, mean age 14 years) underwent a DMSA study for several renal diseases. The relative renal function, based on the relative DMSA uptake uncorrected and corrected for renal size, and the absolute renal DMSA uptake were calculated. In order to relate the relative DMSA uptake uncorrected and corrected for renal size with the absolute DMSA uptake, subtraction of uncorrected (SU) and corrected (SC) relative uptake percentages of each pair of kidneys was obtained, and these values were correlated to the matched subtraction percentages of absolute uptake (SA). If the individual relative renal function is normal (45%-55%), the subtraction value is less or equal to 10%. Results: In 227 patients (51%) the relative renal DMSA uptake value was normal either uncorrected or corrected for renal size (A), and in 149 patients (34%) it was abnormal by both quantification methods (B). Seventy-seven patients (15%) had the relative renal DMSA uptake abnormal only by the uncorrected method (C). Subtraction value of absolute DMSA uptake percentages was not significantly different of subtraction value of relative DMSA uptake percentages corrected for renal size when relative uncorrected uptake was abnormal and corrected normal. where * p<0.0001, and p=NS. Conclusion: When uncorrected and corrected relative DMSA uptake are abnormal, the absolute uptake is also impaired, while when

  14. Immunological functioning in Alzheimer's disease: differential effects of relative left versus right temporoparietal dysfunction.

    Science.gov (United States)

    Foster, Paul S; Roosa, Katelyn M; Williams, Megan R; Witt, John C; Heilman, Kenneth M; Drago, Valeria

    2013-10-15

    The cerebral hemispheres are differentially involved in regulating immunological functioning and the neuropathology associated with Alzheimer's disease (AD) is asymmetrical. Thus, subgroups of AD patients may exhibit different patterns of immunological dysfunction. We explored this possibility in a group of AD patients and found that patients with low white blood cell counts and low lymphocyte numbers exhibited better performance on tests of right temporoparietal functioning. Also, a significant positive relationship exists between lymph numbers and performance on a test of left temporoparietal functioning. Thus, some AD patients have greater immunological dysfunction based on relative left versus right temporoparietal functioning. © 2013.

  15. Relation between fluid intelligence and frontal lobe functioning in older adults.

    Science.gov (United States)

    Isingrini, M; Vazou, F

    1997-01-01

    This study reports the relations among normal aging, intelligence, and frontal lobe functioning. Intelligence tasks and frontal lobe functioning tasks were administered to 107 adults from two age groups (25 to 46 years and 70 to 99 years). Intelligence measures were assessed with two crystallized tests (WAIS Vocabulary and Information subtests), one fluid intelligence test (Cattell's Matrices), and one mixed, crystallized and fluid test (WAIS Similarities subtest). Frontal functioning was assessed using the Wisconsin Card Sorting Test (WCST) and two tests of verbal fluency. Significant age differences in favor of the young were found on the two intelligence tests with a fluid component and on all measures of frontal lobe functioning. Correlational analyses examining the relationship of intelligence measures to frontal variables indicated that these last measures were significantly correlated with only fluid intelligence tests in the elderly group. The implications for the relations among aging, fluid intelligence, and frontal lobe functioning are discussed.

  16. Dopamine enhances duodenal epithelial permeability via the dopamine D5 receptor in rodent.

    Science.gov (United States)

    Feng, X-Y; Zhang, D-N; Wang, Y-A; Fan, R-F; Hong, F; Zhang, Y; Li, Y; Zhu, J-X

    2017-05-01

    The intestinal barrier is made up of epithelial cells and intercellular junctional complexes to regulate epithelial ion transport and permeability. Dopamine (DA) is able to promote duodenal epithelial ion transport through D1-like receptors, which includes subtypes of D 1 (D 1 R) and D 5 (D 5 R), but whether D1-like receptors influence the duodenal permeability is unclear. FITC-dextran permeability, short-circuit current (I SC ), Western blot, immunohistochemistry and ELISA were used in human D 5 R transgenic mice and hyperendogenous enteric DA (HEnD) rats in this study. Dopamine induced a downward deflection in I SC and an increase in FITC-dextran permeability of control rat duodenum, which were inhibited by the D1-like receptor antagonist, SCH-23390. However, DA decreased duodenal transepithelial resistance (TER), an effect also reversed by SCH-23390. A strong immunofluorescence signal for D 5 R, but not D 1 R, was observed in the duodenum of control rat. In human D 5 R knock-in transgenic mice, duodenal mucosa displayed an increased basal I SC with high FITC-dextran permeability and decreased TER with a lowered expression of tight junction proteins, suggesting attenuated duodenal barrier function in these transgenic mice. D 5 R knock-down transgenic mice manifested a decreased basal I SC with lowered FITC-dextran permeability. Moreover, an increased FITC-dextran permeability combined with decreased TER and tight junction protein expression in duodenal mucosa were also observed in HEnD rats. This study demonstrates, for the first time, that DA enhances duodenal permeability of control rat via D 5 R, which provides new experimental and theoretical evidence for the influence of DA on duodenal epithelial barrier function. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  17. Comment on star–star relations in statistical mechanics and elliptic gamma-function identities

    International Nuclear Information System (INIS)

    Bazhanov, Vladimir V; Kels, Andrew P; Sergeev, Sergey M

    2013-01-01

    We prove a recently conjectured star–star relation, which plays the role of an integrability condition for a class of 2D Ising-type models with multicomponent continuous spin variables. Namely, we reduce this relation to an identity for elliptic gamma functions, previously obtained by Rains. (fast track communication)

  18. Parents with Psychosis: A Pilot Study Examining Self-Report Measures Related to Family Functioning.

    Science.gov (United States)

    Plant, Karen; Byrne, Linda; Barkla, Joanne; McLean, Duncan; Hearle, Jenny; McGrath, John

    2002-01-01

    Examines the utility of various self-report instruments related to family functioning in families where a parent has a psychotic disorder, and explores associations between these instruments and symptoms in the parent. There were significant associations between objective measures of negative symptoms and self-report scores related to problems in…

  19. The Effects of a Local Negative Feedback Function between Choice and Relative Reinforcer Rate

    Science.gov (United States)

    Davison, Michael; Elliffe, Douglas; Marr, M. Jackson

    2010-01-01

    Four pigeons were trained on two-key concurrent variable-interval schedules with no changeover delay. In Phase 1, relative reinforcers on the two alternatives were varied over five conditions from 0.1 to 0.9. In Phases 2 and 3, we instituted a molar feedback function between relative choice in an interreinforcer interval and the probability of…

  20. INTESTINAL PERMEABILITY IN PEDIATRIC GASTROENTEROLOGY

    NARCIS (Netherlands)

    VANELBURG, RM; UIL, JJ; DEMONCHY, JGR; HEYMANS, HSA

    1992-01-01

    The role of the physiologic barrier function of the small bowel and its possible role in health and disease has attracted much attention over the past decade. The intestinal mucosal barrier for luminal macromolecules and microorganism is the result of non-immunologic and immunologic defense